If you boil them for about 1-2 hours it should make all of the meat slide right out. Then if you lay them out in the sun they should get nice and white too. The biggest problem with that though, is sometimes the edges will get brown, so a bleach bath should do the trick also.
Also, for people that are doing this often, they sell worms at feed stores that live off of flesh and only need to be fed about once ever two months. They will pick the bones clean in about a half hour.