Mix up a batch of “ Ed’s Red “ and cleaning up carbon in gas pistons is easier and cheaper than using store bought. I just drop the piston in a glass jar contains the mixture let it soak a few minutes then remove and wipe off. I apply a light coating of Break Free after cleaned.
Same with cleaning off the mag tube and inside the forstock. Carefull with synthetic stocks.
Does a great job on plastic wad build up in barrels and choke tubes as well.
Just Google it and you’ll get mixing info.