HK USP Tactical / AAC suppressor

I just got back from the range for just the 3rd time using my HK USP Tactical with the AAC Suppressor. I have always shot the suppressor dry and it was always pretty loud - loud enough to need hearing protection. But today I went ahead and loaded it with water to see what it was like wet. I could not believe the difference! I thought I'd get just a few decibals less but it was night and day. I could hear the bullet hit the paper and the backstop. It actually sounded somewhat like the movie silencers. It did tend to spray a bit of water/oil flecks on me but it was totally worth it.

I want to try oil next. Has anyone tried oil in their suppressor?