First off, most nail polish is lacquer...
Military ammo is sealed much more than any civilian ammo needs to be. In some cases, military ammo is stored under water!
I've got handloads I made up in the late 70s that still fire just fine. Done right they will probably outlast you. And no sealant was used.
Buying new 06 to turn into 8mm is foolish. 8mm is out there, as new brass. And if you hit the gun shows, odds are good you can find "once fired" for not too much (but beware, some people think it's gold, not brass) Look for estate sales, too. Lots of older folks passing, their stuff being sold for not too much.
If you find a bunch of someone else's 8mm handloads, (cheap) grab them, and pull them down for the cases (and maybe the bullets) toss the powder, even if you THINK you know what it is, toss it, anyway. Simply not worth the risk.
You CAN anneal anytime you want, but just to form 06 into 8mm Mauser, I wouldn't bother.
The only plus (besides the price) to the European spam can is you get the stripper clips. The down side, corrosive priming and berdan cases (so even if its brass, its scrap metal once fired. And it might be steel cases...)
Don't overlook US made, ammo, Remington, in particular. (I haven't seen Winchester 8mm in ages, but one still sees Rem Core-lokt 8mm Mauser. The bullets are good, the brass is as good as it gets. The load is mild, a few hundred fps below what European ammo is loaded too. Always been as accurate as anything in the stock Mausers I have shot it through. Not dirt cheap, but buy a box, here, another there, next month, or what ever, save your brass and soon you'll have a bunch...
I'd only form 8mm brass as a last resort. I formed 7.7Jap, until I got some commercial brass, its a bit more scarce than 8mm Mauser.