I have been shooting 7N6 in a Saiga for a year. Though I have a lot of corrosive ammo experience, I find the 5.45 to be the most corrosive ammo I have shot.
I ended up buying a bottle of RemOil rust preventative CLP, which I apply after doing the hot water clean. This seems to work.
I have just started using Ballistol mixed with water for my clean up. So far, so good.
The 7N6 is a fantastic cartridge, and the 74 platform with muzzle brake seems to be the least recoiling serious cartridge I have ever fired...in rapid fire, I can actually feel the brake pushing the muzzle down...
Still waiting for my Flashback...I would like it now, please.