Taking dbol alone is not usually a good idea. It's very toxic to the liver and gains disappear very quickly. Stacking it with non gear doesn't remove the problem. I use it at the start of a cycle before other gear kicks in, about four weeks.
This goes against what most people believe but...
I've read that clen has an anticatabolic effect and some claim it can help add muscle mass, although I personally doubt this. Anyway, clen should not cause you to lose muscle mass.