You are right, Rebecca,
Cats naturally love to scratch and make sure to cover up any smell before they leave the place.
We have also had cats for all of my life, and tried all of your mentioned methods - and then some..
Sawdust in Cardboard box works, pelleted sawdust* or shredded corncob crumbs work even better,
- in terms of dusting & tracking a little less. (A friend had constructed a pellet press for his stove..)
And, with a little added baking soda, they both do a halfway decent job in inhibiting smell.
However, like Sheri said, since it doesn't clump, you always have to scoop out a lot each time,
and empty the whole amount out every few days, which is using A LOT of said material,
and the tracking inside a house is still quite an annoyance.
Newspaper in a box is very beloved by cats. (Just try letting a cardboard box with your recycling-bound papers
sit around for a minute or even just a half without looking before bringing them out... - They'll be in there faster than you can look!)
But still, that creates a LOT of waste, since you have to throw out everything every time, - with NO smell inhibition whatsoever.
Sand, while cheap in some areas (we'd have to haul it from the beach ten miles away or buy it in the store..)
is in this regard not much different. Since it doesn't clump, but on the contrary drains especially well,
it soaks very quickly all the way through, - when you have cardboard underneath, saturating the cardboard before wetting the floor..,
if you have it in a plastic box, forming a lake at the bottom.. - and thus has to be exchanged completely, almost every time,
- all while providing very little smell inhibition.
With that, all of these methods have their challenges which, with more than two cats, over time, are rather tough to brave.
This led us to the entire elimination of the litter, eventually. Which, as said, works well for us with no sustained costs and minimal time effort.
The cats might need to be younger to accept the change well (like with most any other change to their routine, - they really cherish their habits).
But when they accept it, they seem pretty happy with it. We tried a box with their old corncob litter again when we had to leave for three days,
and more than half of the cats still preferred their empty box/bathtub they had meanwhile gotten used to.
They do scratch on the sides of the empty boxes or in the tub, but are ok with the result, since - I made it a point to clean up right after them,
whenever I heard them scratching, and caress them whenever I saw them going in there.
(Which - due to the incomparably greater effort rquired, I hadn't done with the litter in the box.)
They seem to have understood, that this way they have a clean space to go every time they need to, and they very evidently do appreciate that.
Sheri, while I don't know about Bokashi, you can certainly compost cat manure. (That's what happens with outside cats' droppings anyway.)
Cats feces are already far more "composted" than raw meat, and not subject to putrefaction anymore.
We use a water flushed composting toilet for humanure. (The toilet pipes run through a simple strainer basket outside, and the runoff is sent through
contained blackwater planters and the already very clean runoff of that thereafter into a leach field. The output of the leach field far surpasses
the very stringent quality requirements for swimming lakes in Germany). The fermentation of the solids in the strainer basket (in a chamber under the soil)
can be aerobic with vent pipe up to the roof and thus completely smell-free.
Or it can be done anaerobically in a airtight tank, with the methane gas from the fermentation made available for cooking...
The humanure solids composted in this manner take about two years to decompose into a rich inert soil, which can be used in the gardening.
(The strainer basket is separated in half vertically, and turned around 90 degrees, when one side is full after one year,
so that the fermentation can complete for one year without added new material.)
We flush the cat feces into that system, too, and they decompose with the humanure.
But, since, with litter free box method, the cats usually use different boxes for wet and dry business,
you can easily just throw the solids, which are nicely separated from the liquids that way, down any compost toilet
(or just dig it somewhere under the surface of your compost heap, or even a specially assigned compost heap, if you wish)
and treat the liquids as you do yours or thin them down for use as highly efficient free N-fertilizer,
(that does not, like straight cat pepee, burn the plants and soil life).
To the food question, - Cats are - due to the very different make up of their intestinal tract
(very short and smooth, with little surface for flora to adhere to minimize putrefaction of meats) -
meat eaters by nature. And trying to force a vegetarian or mainly vegetarian diet upon them,
that would be ok and healthy for humans (with our long rough and extremely folded intestines
which relay on nurturing a rich intestinal flora to break down herbal material), would NOT be healthy nor natural for a cat.
Especially grains and pulses (legumes like beans) the overeating of which already produces enough problems in people,
is anything else than natural, let alone healthy, for cats (Imagine a cat harvesting grains or cooking beans!... -
(The fresh beans would anyway kill her before she could make it a habit..))
Of course, if your cats still get their main sustenance from hunting for mice, they might survive that kind of vegetarian supplement,
but it is not healthier or more natural for them to eat than a highly processed mainly flour & starch &/or sugar based diet for humans,
- with a very similar poor long term outlook.
Fish is good, - as long as it is the kind of fish would be able to catch themselves.
Big ocean fish on the contrary who are far higher on the food chain do, due to the large amounts of
heavy metals and other toxins they accumulate in their tissues, have a very detrimental long term effect on cats.
Cats also do need to eat WHOLE fish, since they depend on the minerals from fish bones, the vitamins and minerals
as wel as secondary micro-nutrients from organs and blood.
A neighbor fed his cats almost exclusively tuna cans, and all of his cats died within one year on the diet.
(They were all adult when he got them. And he got each one the after the death of another.)
(He finally switched to giblets, sardines, salmon, tilapia & beef heart, the last cat became 18 years old and is still strong.)
(While sardines, salmons, chickens & cow organs are not the most natural prey for house cats either,
the more varied mix seems to at least provide what the cat needs to live a long life.)
As to milk and cream, - Almost ALL cats are highly lactose intolerant after weaning time
(They just don't ever get to milk a cow or goat or sheep in Nature..),
and the resulting bloating and often violent diarrhea dairy consume causes them, is painful
and not a particular act of love to provide them with.
Water is really best for them.
(Since cats on a natural diet get about 80% of their water needs from the meat they consume,
they need a lot more than feral cats, once you feed them things that differ from their natural diet/ are not meat.)
All the best!