Inexpensive natural plaster

I need an inexpensive natural plaster for inside my future rock roundhouse. I live in the Ozarks I arkansas and get quite a bit of rainfall as well as an extremely humid climate. Also how would I run electric through my walls with natural plasters in rock house with out framing with wood. I don't mind having a skeleton on the inside if that is a must for plaster. Thank y'all for your help!

As for electric cables, they can run within the plaster, or even better in the gaps between the stones. There are also flat cables in case the normal ones are too thick (about half as thick, but twice as wide).
Placing outlets is the tricky part. Those that are mounted on top of the plaster are far easier to install, but take up a lot more space in the room. Those flush with the wall require a hole in the wall, which could be a challenge with a rock house.

One solution (to cables and outlets) might be to create raised bands in which the wires run, and mounds for the outlets. That also solves the problem of not knowing where the cables are later and it can be made to look better then cables running everywhere.

As for the plaster itself, you can basically combine base material, mechanical modification, and coating:

Base materials:
- clay / sand mixture: good water absorption, strength varies with mixture. Can be very thin.
- clay / perlite: very strong, lighter and somewhat insulating. Can't be made thinner than the perlite particles.
- lime / sand: can be strong or weak. (I have no experience with it)

Mechanical modifications:
- uncompressed: best water absorption, weaker, rough, matte.
- compressing with a scraper: a bit stronger, smooth, glossy.
- compressing with a (plastic) hammer: strongest, uneven surface.

Coating:
- none
- water glass undiluted: seals the surface and strengthens it.
- water glass diluted with water: strengthens the surface and but keeps it open.
- linseed oil: strengthens the surface and seals it. Water resistant.
- soap: seals the surface and makes it water resistant.

A combination of lime plaster, compressing by scraping and soap is called Tadelakt.

Pigments:
Inexpensive pigments can be added to the coating directly.
For expensive pigments, it makes sense to apply a base-coat that seals the clay/lime, then a thin coat with added pigments and optionally a third one to protect the pigments against wear.


EDIT: Rewrote to make easier to follow.

Thank you Sebastian. Do you know where I can find diagrams of this type of wiring? And what exactly do you mean by raised bands? So you mean wiring while plastering, covering the wire with plaster?

Yes, I meant to cover the cables with plaster (which itself could turn into a bit of artwork to make it pretty).

As for the schematics, I recommend finding someone locally who is comfortable with electricity.

As for wiring in Germany: The outlets in a room are connected by a cable that runs between them and then to a breaker at the switching board for the living unit (might be a small house or just one floor).
So you end up with a central switching board that has a cable running to every room.

That wiring pic is actually really helpful when visualizing the setup. Not enough natural building work covers the options there(with pictures). Lots explain it, but this picture is much more clear.

you ain't kidding Bill that diagram is exactly what I was looking for. thanks again Sebastian! what is your favorite earthen sustainable plaster?