How to clean pots and switches properly?

I got a good deal on a vintage Yamaha cr-420 receiver on ebay for a second A/V system..

THis is a very nice sounding vintage receiver and I am very pleased with the sound, including phono section, but I think the pots need cleaning. When I power up, the left side crackles and the right side does not cut in until the volume is increased. Once things warm up, the volume control seems to operate fine.

What's the right way to clean the switches and pots as needed?

Also, after tuning a channel, I've noticed that FM stereo typically will not activate until I depress and release the fm stereo button, which does not seem normal to me. IS there anything that can be done about this?

Other than these two quircks, the Yamaha has really impressed me (as I recall from many years ago) as one of the better sounding receivers I've heard.