I skin a head then bury it in the flower bed for about 4 to 5 months checking after 3. Less time for warmer climates. Put a bucket or storage tub over the top staked down to keep anything from digging it up. Then just soak in water, scrub clean and let dry completly. I glue teeth in with Quicktite superglue. Not the cheap stuff. Then spray a coating of Krylon satin finish on it. Top, bottom, everywhere you can get the spray to go. Drys to the touch in ten minutes. This seals the bone and the teeth. I've done many a skull of all different animals, both bleached and this more natural look that I have just described. Everyone I have asked likes this look much better than the bright white finish. I like it better to. A bleached out skull looks as if it were brought home from the desert. If you have never done a natural one and have the patience to wait a few months, gives you something to do in the late spring to bring back those memories, try it and see what you think.