I try and avoid bleach as it makes the bones fragile. I often used a clothes washing powder for a final clean though they probably have a small amount of bleach in them.
On skulls, I really like these three tiny ear bones which came from a domestic pigs skull - the malleus, incus and stapes - which translated into english are hammer, anvil and stirrup. I get why the little one was called a stirrup not sure where they got the idea of a hammer and anvil from...
I've been thinking and reading about 3d printing. Either fdm or resin which seems to be getting cheaper. I have seen people mention that some printed parts for rc snap too easily either due to lack of strength or flexibility. Do you have any thoughts on printer types or which materials are best...