I've read about folks using everything from Sweet's to brake cleaner, but I haven't seen any point-for-point comparisons.  Here's what I want in a solvent:

1)  Disolves powder residue and fouling (barrel, bolt carrier, carrier key, muzzle, wherever...)

2)  Degreases, removing grease (including molydenum disulfide grease), oil, and composite products (like CLP)

3)  Is compatible with the plastics used in firearms (not just AR parts, what about Glocks?)

4)  Does not include an MSDS that reads like a Superfund Cleanup Site (no respirator/vent hood required, nitrile golves at most)

5)  Does not, by itself, leave any residue (though it may leave uncleaned crud if not used properly and/or thoroughly)

I don't think most of us need to worry about copper fouling as much as getting caked on gunk ("Oops!  Too much lube, and now there's soot and powder fouling in it!") out of various parts of the rifle.  I personally want to be able to strip off anything outside the phosphate coating, leaving the parts completely clean-and ready for appropriate lubrication.

What are your thoughts on the various products on the market?  I don't care if they're "gun" products, machine shop products, or cosmetic products, just so long as they work.

hot prerssure washer @ 3000 PSI will work.  You will need some thick gloves.

Strike-Hold does all those things

www.strike-hold.com