Is it ok to use Faderlube on switches that have multiple function all in one switch? For example one switchable knob wiith Phono, Turntable, AM,FM as choices.
It's not intended for that, but I agree with Frank: I doubt it can harm. It might even help, by protecting the plated contact-points — but only if it stayed in place, switching between sources will probably wipe it off fast.
I've honestly never liked anything but non-residue cleaners on switches like that. My usual is CRC QD. Anything that leaves a film behind tends to attract dust, which leads to electrical leakage in the switch. When that happens you get bleed-through from other sources. Stuff with open switched that have phenolic wafers are really bad about soaking up stuff and causing headaches.
I will also admit to not being a huge DeOxit fan specifically because it leaves residue in switches and it has caused me problems in the past. I also think its a bit too spendy for what you get.