over the years i have gotten a few euro mounts done before i started doing them myself. couple of my old ones are starting to get yellow/dirty look above the teeth area and i checked, its not dust. can i just take them back off the plaque & re apply the whitener? i dont think they would survive another cooking since they are a few years old.

thanks

Im sure its a little grease. Alot of times it will start to surface there and on top of the head where the brain was. A good soak in dawn dish soap and water for a few days should do it. When its this hot out and the water stays hot it dont take long and this wont make the bone brittle.