Do avocado stones or skin have any medicinal uses?

You’re right, the peels don’t compost very well with other things but they do dry up nicely if left out in the sun by themselves, they get crumbly and then mix in with other stuffs. About the pits/stones, my mom used to chunk them and crush them in a garlic press and the strained mash got put into a cheesecloth she would rub on her skin in the bath. I haven’t tried it, totally forgot about it until now.

Here is an excellent article about the composition of the avocado seed.

See why this article calls avocado an R-rated word, includes information on recepies for the pit (seed).