Gotta agree with you and Manny's post above. I have an acrolite with the ball bat muffler and it's either on or off.

I haven't attempted to use the mufflers since I bought my Super Classic set back in 1968 ...I was in a garage rock band , and tended to play pretty hard , mostly in order to be heard over the Fender Dual Showman and Vox Super Beatles amps my bandmates cranked up high lol . But some songs were much lighter in nature and I'd engage the mufflers sometimes . 5 minutes of light playing and they would inevitably disengage , Bloody useless , more useless than 50's/60's bass drum spurs that didn't work either . One had to put something in front of the bass drum to keep that baby from sliding away . Never had a problem with Rogers or Gretsch of the same era .