Synth Cleaning Guide / Suggestions

Hey all, I just recently bought a secondhand synth (Drumbrute Impact) and it's fairly crusty and nasty. Are there any good resources for how to go about cleaning? Most of what I'm seeing online is just your normal care guides, and not deep cleaning.

In particular, I'm wondering...

• Do I need to take the synth apart completely? Especially with regard to cleaning the case itself; I'm worried about e.g. water getting inside and messing something up if I don't remove the top case
• Can I remove all of these knobs?
• What chemicals / cleaners and brushes would be safe to use on the buttons, pads, and knobs? The pads/buttons look to be screen printed, and the knobs are that rubbery / soft-touch plastic