After paying for a couple of clean and bleach/euro mount jobs a few years back I started trying to do my own. My first attempts were on a hunting trip to Montana. My uncle had a few deadheads collected in his shed. We didn't wind up making it halfway through the mule deer collection, and there are as many if not more elk heads to be done at some point. Quite a project. This chance to experiment over the course of a few days was a big help in getting going in the right direction for a simple, repeatable process that seems to work really well.
After looking at a bunch of stuff online and then getting into the process, I have a layman's recipe that works very well for me for DIY clean and bleach euro mounts. I've used this method on un-skinned heads that have sat around for years, as well as freshly killed, skinned, and carefully picked heads. The results are good with both.
The way I've been doing involves basically 5 steps:
1) Peel and pick the skull as much as you can before boiling
2) Initial boil, 1-2 hours or until everything is soft, not so long that teeth fall out and skull plates get loose.
3) Pick, clean, and powerwash the skull
4) De-greasing boil with oxiclean, 30 min to an hour
5) Whitening boil with peroxide, 30 min to an hour
I haven't paid close attention to boil times, water to oxiclean ratios, and water to peroxide ratios, but rather just winged it and kept an eye on progress as things went along. With 3% peroxide, which is what I used initially, I think I was at about a 1 gal to 3 gal ration of peroxide to water. More recently I've been getting the larger qty, higher concentrate peroxide from beauty supply stores, 40vol is ideal as you don't have to use as much. I have had the best luck adding the peroxide to water and doing a whitening boil to finish. I have tried the cream form in higher concentrations, painted the skulls in cream and letting them sit, but I wasn't quite as happy with that method.
There are lots of other little tips and tricks that help like wrapping and taping the antlers or bases, etc. I almost always have to wind up touching up the bases of horns and antlers with some stain which is easy to do and easy to get right.
I don't have pics of the finished products handy, but I can add a few later on.
I've used the process above on goats, sheep, and mule deer all with similar results

Deadhead collection

Brain soup