Volume Control Cleaner & chassis lube?

[LCC0256]

Will someone please tell me exactly how to go about cleaning volume controls on my radios? I have several table top models from the 1940's thru the early 1960's all American Manufacturers.... as i understand it many times the extra crackling noise emitted during turning set on and off can be eliminated by cleaning the volume control (which in the case of my current radios are also the ON/OFF switches.) Also as for the tuning dial mechanism with the cord attached... does it ever need lubrication and if so should it be cleaned first? if so what cleaner & what type lubricant? Thank you very much for your help.