.22 cal suppressors have a particular problem with carbon and lead fouling. I have a Gemtech Outback IID, which is a user-serviceable suppressor, but I found out that it was absolutely necessary to clean it after no more than 100 rounds, or it was nearly impossible to remove the baffle cones from the sleeve, especially when using "dirty" subsonic rounds. I had to practically beat them out or use a tool like a crochet hook to coax them out, after liberally wetting them down with a cleaner like Slip 2000. Recently, however, I discovered FIREClean anti-fouling gun conditioning oil. I followed the manufacturer's directions for cleaning the metal, conditioning it overnight, and applied a thin coat to all surfaces before reassembling the parts. I went to the range today and put over 100 rounds through the Outback. When I got home I disassembled the suppressor and it came apart far easier than it has since I owned it. Carbon and lead particles came out with the baffles. No pounding or hard pulling to get the baffles out. I conditioned it again tonight and I'll apply another thin coat to get it ready for the next range session. The FIREClean folks claim that with each use, the metal becomes more conditioned and even more fouling will come off. Time will tell. So far I am very pleased, and I wonder what my results would have been had I conditioned my suppressor before I ever put the first round through it.
I'll update as I find out more.