The stickiness is due to the rubber coating breaking down so no amount of soap and water will help (in fact it will clean off any sort of dirt and oil and make it worse!)
What I did find elsewhere is that regular isopropyl alcohol (‘IPA’) will actually dissolve the rubber bond so with some soaking and a toothbrush I was able to completely strip off the rubber.
The knobs no longer have that nice soft-touch coating but still much better than the stickiness. (IPA is also called rubbing alcohol but that is 70% water. Go to a hardware store and find the 95 or 99% stuff)
Note: Do not try Acetone! Yeah it strips off the rubber like mad but also starts melting the knob itself. They are probably made of ABS and you can literally dissolve ABS in acetone.
HI @shadowphile
Yep, this stuff has affected quite a few companies in the past few years, even Maserati sports cars!!
I had issues with a Nektar P6 which has A LOT of knobs/faders/wheels covered in it. I noticed mine had degraded, after grabbing one of the faders and my fingers stuck to it!
I found leaving the affected bits in a sealed polythene bag in direct sunlight for a few weeks helped MASSIVELY before using, as you said, IPA. I found the sunlight broke the coating down even more and i was able to just rub the stuff off with a bit of 70% IPA and a microfibre cloth.
If i’m honest, i just forgot about them and left them on a windowsill by accident lol
You MIGHT be able to sources some replacements if log in to your account to contact our support team they MAY be able to help or direct you to some replacements.
HTH!
This happened to my JBL LSR 4328P monitors and last year was told to try Clorox wipes. Worked like a charm! So I used them on all my sticky plastic stuff.
I used Rubbing alcohol as you did but at only 70% strength and it cleaned the sticky stuff off and kept the rubber on underneath. Hope this helps