It's amazing how well the Deoxit contact cleaner works for sockets, tube pins (I use an old tooth brush for just a couple of swipes) and pots. Makes many amp issues go away ! By the way, there are other brands that work equally as well. Just make sure for sockets you use one without a lubricant. https://www.homedepot.com/p/CRC-QD-1...E&gclsrc=aw.ds
The ones with a lot of lubricants should be used for pots and areas were there is not at much heat, but someone please chime in if I got that part wrong. I've been using Deoxit D5 in tube sockets with no issues so far.
You might have to do this once every few years, but doing it right the first time makes sure it will last a long time.