If you scroll up you can see how I set up the sonic cleaner. Three silencers and two AR-15 BCGs in a glass pan filled with Break Through. A gallon of tap water in the sonic cleaner outside of the pan. No damage to the silencer sprayed on finishes. The phosphate finish on one BCG and OPS Inc can (not pictured) are chaukie. I don't think they are damaged either, just absolutely spotless and oil free. The first silencer in the picture series is a TBAC U7.Did you put the cans directly in the US?
Did it effect your coating at all?
I soaked a silencer plugged at one end for 4 days, two hours in the ultra sonic cleaner is about the same, if not better.