Gunsmithing DIY Solvent's

I've been using 50% synthetic 30 weight oil mixed with 50% automatic transmission fluid. I use it where I want a light film of oil.

If I want it to clean I add in 10% fuel injector cleaner.

It is simple to make but works well.
 
That is a great resource. I just started using Ed's Red and the Piston Kleen that he talks about on that site. Both work very well for their intended uses. I have a small US cleaner with the Piston Kleen in it that cleans muzzle brakes really well if you leave it soak over night and then agitate it for a few minutes.