When I first built this, we just used a bucket situated underneath. The bucket was wider than a standard 5 gallon bucket and it was easy for both of us to use, but both wastes would mix together. This meant a lot more saw dust, and no matter how much you put in it would still pool at the bottom of the bucket and go stagnant quickly.
I had read a post on here of a much more elaborate diy toilet, so I just simplified my version and made it a short project. Credit for some of what I did goes to that guy or gal, it was awhile back that I read the post so I don’t remember.
I used a 5 gallon bucket for the funnel, and used a heat gun to soften the plastic and cut it to its base form. After a few attempts and fails I got the shape right, and from there used to heat gun to mold it into a better shape and to fit it in my toilet box.
Shaved and trimmed the funnel to fit well with the bucket, and curled up the back to prevent spills. I tried to just heat and mold the bottom of the pee diverter into a funnel like the original poster of this idea, but my skills lack in the plastic molding dept. So I took a mini plastic funnel and heated it up and molded it over the hole id made, then used a quality silicone caulk around it and let it cure. It does not leak at the funnel.
The box is made from a single 4’x8’ sheet of ½ inch birch plywood, and stained with linseed oil.
There is a black plastic bag that lays flat on the floor under the bucket and piss jug. This is to catch accidents if someone misses the funnel or bucket, which has happened. Misses are just something we have gotten used to once in awhile, I am sure with more trial and error and more destroyed buckets I could get it just right but the time… So we just deal with it being slightly more inconvenient than a flushing toilet. The benefits of living this way are huge, and a little taboo about your bodily waste shouldn’t steer you away from your dreams and the possibilities that come with owning a tiny home or not needing plumbing or septic. The money saved is far superior to any inconvenience of this lifestyle.