I clean mine real good when I first get them as they have a black gunk in the barrel. After that I clean mine every 40-50 shots. I always shoot a fouler after cleaning prior to shooting for groups. I drypatch between shots too.
Loggy turned me on to the CVA advanced Sabot Shooters Solvent, and that is what I use to clean with. That and Carb. cleaner!
I remove the breechplug, spray it with carb cleaner, brush it with an old toothbrush and spray it off, then remove the ventliner, drill out the carbon and spray it out and rinse with the carb cleaner. Then I spray the barrel breech plug threads with carb cleaner and use my breechplug brush a couple of swipes then spray it out again. Then I clean the barrel with the sabot solvent, put the "Stick" never seize back on the breechplug, wipe the rest of the breechplug with Breakfree and reinstall. Then I wipe the gun down on the outside with Breakfree and all done. Takes about 30 minutes tops, but I am thorough and maybe a little slow.