you can coat them with a shellac or varnish if you like - it might keep them from chipping or cracking, but it will not change the overall integrity of the bone.
It’s truly up to you and your aesthetic i suppose - i like bones to look really natural but as ripewickedplum said: “epoxy would harden and stregthen it!”
in general: older, weathered bones are more likely to chip and fracture.
but all in all: intact bones are pretty strong - they should hold up just fine to every day wear. Just make sure they take them off before showering/bathing or any sort of rough-housing.
Honestly, most end up washed partially in my tears.
I mourn each and every animal that was killed because humans think they ‘know best’ or ‘are allowed’, or because that animal was deemed a ‘pest’ …. i cry because i don’t understand how you kill something so beautiful . … because sadness is the appropriate response to a senseless death.
I clean them, carefully, lovingly. I bath them in essential oils and incense smoke the way I’ve seen done in old religious ceremonies. I treat them as Sacred. I name them, i find a good place in the house for them to be safe (often by a window or with other similar animals) and i talk to them often - reminding them that not all humans are thoughtless and cruel.
luckily i don’t live in a ‘ranching’ area, and this side of Washington is pretty aware of the impact humans have on wildlife.
i mostly come across roadkill. Which in reality is no less sad - we build a road through their home, fill it with Super Fast moving cars, trucks and trains and then - when they’ve been struck - we leave them there on the roadside like garbage. it’s horrifying.
okay, i’m gonna go hug my cats and try not to cry now….