I would give the attenuator ten or twelve full rotations quickly, just to burnish the contacts a little bit and remove any oxidation.
When we first got the switches in that go with the BeeQuiet and Submissive, I built up an attenuator and it popped during switching. I was pretty disappointed and was ready to throw in the towel, but Doc B. suggested contact cleaner and several rotations, which completely solved the problem.
-PB