It is okay to use Break Free gun scrubber or some other areosol degreaser in my AAC Pilot?

I would use mineral spirits, the instructions call for Kroil. But honestly, none of it seems to make any difference. I've yet to rinse out any significant amount of crud from a .22 can. There was a thread on subguns a while back where someone took a cheap orbital sander and made a mount & container in which they placed their silencer and solvent and ran the sander as a poor mans ultrasonic. You'd have to make sure the silencer itself wasn't free to slide around in the container or it would ruin the finish.

I'm not worried about getting it clean.  I'm worried about any O rings that are in it.

Well AFAIK, there are no o-rings in a Pilot, haven't seen a sealed .22 can yet that had o-rings in it. I would be more worried about a solvent that attracted condensation, the non-chlorinated solvents will do this. Also if the solvent is volatile like gasoline as you could have a detonation. I don't like the Kroil that AAC recommends because it stinks so bad when it is burnt. Stick with mineral spirits & compressed air and you'll be fine.

Good, that is what I was worried about is if I was going to melt an O ring.