All the Romanian made WASR rifles have chrome lined bores and chambers.
That's why you need to be careful how you remove the corrosion. Damage the ultra-thin chrome lining and the rifle will corrode faster and may give extraction problems.
For a chamber brush, buy a BRONZE (not stainless) one from Brownell's. To use, stab it into the chamber and rotate a few turns. Pull out and repeat.
Don't wrap it with a patch, that ruins the brush:
http://www.brownells.com/.aspx/pid=1...HAMBER_BRUSHES