
What you want to do is get a Dermestid colony and set them up. There are charts to see what size colony you need for the size of skeletons you want to clean and how long it will take. A skull for example:

Requires you to remove all the heavy meats such as the tongue, eyes, and brain. Then you have to let the meat dry for a time to get a nice jerky consistency. You can do this artificially with drying rooms or you can just leave it in a warm, dry place. Be warned though, you will attract flies and that's not the kind of crowd you want doing your taxidermy work. After the meat is dry, you just toss it in the colony making sure you don't crush any of your workers. They will go to town on it and within a few days, depending on the size of the object, it will be clean. After that you clean any bits that the bugs didn't and dunk it in peroxide. Leave it there for a few days and it will whiten the skull without making it brittle.
The bigger the carcass, the more bugs you need. The bugs themselves need a few small bones here and there to live in along with some sort of substrate type material.

Your best bet is to do this outside away from your home and to lock it down tight. The smell of dead animals will attract all sorts of scavengers to your box.
Side note:
You can feed a lot of chickens cheaply with maggots. Take a bucket and drill a bunch of holes in it and then fill it up with rotten animals. Flies get in and lay eggs and maggots are born. Then dump the maggots out for the chickens.