Eml synthesizers

I have the presumably newer Mexican made pots on my 101. Any 
tips on getting into a noisy one to clean it out? I've removed the 
worst one and inspected it but I can't figure out how to open it or 
even get cleaner inside (as a poorer alternative to not openning 
it) without destroying it.

 I can't remember the brand but I saw the same make and size 
pots on a 1968 Moog modular only they were American 
manufactured and looked much easier to get inside of.

Also certain waveforms on osc 4 can be set to leak in the audio 
path when chosen --even if the osc's output is set to zero. Is this 
a design flaw or a problem on just my unit