With the fall archery season in full swing and my buddies layin' over bucks left and right, I decided to post an e-mail I sent to a friend of mine last year describin' my process for a European-style skull mount. Hopefully it'll help some of y'all...
First thing's first, the info that I give you is my preferred method that has served me well for dozens of skulls. If you peruse the internet, you'll find a lot of different methods for doing it. Just like anything else, some are better than others and you have to find the one that works for you.
One thing to keep in mind is you probably don't want to do this in the house if you can help it.... it gets kind of stinky. I used to use a camp stove... I now have an old kitchen stove that I can hook up to a propane tank out in the shop. Be prepared to take anywhere from three-five hours to do it.
First thing you must do is get as much of the crap off of the skull as humanly possible... not always a pleasant task. Start by skinning it out, then cut away as much of the meat you can get to. Once you have the meat trimmed away from the area behind the eye sockets, you should be able to coax the jawbone apart from the skull. Once that's done, it's a lot easier to get the eyes out as you can cut away the connecting tissue from underneath. Clean as much of that junk out as you can, and trim off the roof of the mouth if you are able (depends on how much it's dried out). If you have the stomach for it, bend a clothes hanger into a scoop and remove as much of the brain as you can get to. A very unpleasant task but it's easier to do it now than after it's cooked.
Once all that's done, I've let them set anywhere from a few hours to a few months... doesn't really matter. Sometimes it seems to clean easier fresh, other times it seems better to let it sit for awhile and let the remaining meat rot. Just don't let it set in direct sunlight as you'll discolor the antlers.
The night before I plan to clean it off, I take plastic wrap and electrical tape and seal off the antlers from the rest of the skull as best as I can. Don't skimp on the electrical tape and stretch it as tight as you can around the base of the antler. This will keep most of your water/chemical mix from reaching and discoloring the antler during the cleaning process. Once the antlers are sealed off, find a container and fill it with several tablespoons of dish soap (to cut through grease/fat) and top it off with hot water, then let the skull soak overnight.
Boiling a skull is a misnomer... the proper way to do it is to keep the pot to a simmer. Boiling will dry out the bone and cause a chipped appearance, and the teeth and nosepiece will likely fall out as well. If that happens, superglue does wonders.
I use an old cheap canning pot from Walmart. I fill up with several gallons of water, two tablespoons of dish soap and one quart of peroxide. I pre-heat the mixture and then place the skull in the pot, then top off with water until the water line is just equal to the base of the antler and all bone is covered. You'll need to add water every now and then as it evaporates. If the jawbone is relatively clean, I won't add it until later as it doesn't have as many nooks and crannies and doesn't take as long.
Let the skull simmer for about an hour. Your suds from the dish soap will likely boil up and over during this time... I keep an empty gallon ice cream jug or something similar to scoop the suds out as necessary.
After an hour, take the skull out and use a knife, tweezers and a stiff plastic-bristled brush to remove as much of the junk as possible. Scrape gently with the knife as you may scrape away some bone if not careful. Take extra time on the back of the skull where the neck joint attaches and the bottom where the jawbone attaches... there is a lot of fat and gristle build-up back there that will need scraped away with the knife. Don't worry about getting it all at once... you'll be repeating this process several times. Don't go crazy around the teeth either, as you'll want to let a little bit of fat there to hold them in place.
From there you'll want to remove and brush/scrape about every half hour or so. Add the jawbone somewhere in this time frame.
Once most of the junk has simmered off, dump your water mixture and start fresh. This time add your water, two quart bottles of peroxide and just one tablespoon of dish soap. Pick and scrape at the skull as the new batch heats up, then put it back in.
For this batch you'll want to remove and scrape about every 15-20 minutes until you feel it's done. The skull will not appear to be completely bleach white until it dries, so don't let a little discoloration throw you off. Once 99% of the junk is gone, consider it done. If you let it go too long, you'll have a similar drying and chipping effect as with boiling.
Once you feel it's done, remove the plastic wrap and electrical tape and spray everything down with cold water. Especially focus on the nasal area and brain cavity to flush any remaining junk out of them. After that, let it sit and dry for 24-48 hours, depending on the weather.
Once it has dried for several days, you will see exactly what you missed as any remaining fat begins to turn yellow. There are some people that will soak the skull in peroxide for a few hours after it dries... I personally have never tried this but it may work to alleviate this discoloration. There are many folks that will brush on paint or a liquefied bleach powder after it dries... I personally feel that this looks very unnatural, but feel free to try it based on how you want it to look when you're done.
It takes a few times to get it right, and even then it's still not a foolproof process. I've done enough of them at this point that most of them turn out the way I want them. I still have the occasional one that doesn't work out as well, but even then they usually still look very clean and presentable.