I have described in the past a technique for cleaning tube pins that I learned from my mentor John "Buddha" Camille many years ago. I'm going to reiterate it here due to the fact that I am stoked at how well it recently solved noise problems I was having in the restoration of an Altec 250SU broadcast console we use here at Bottleheadquarters for mixing to two track tape. This console is packed full of high gain 6072 tubes and if you are using all of the inputs you have about 30+ tubes potentially adding noise to the mix.
Take a Q-tip, cut it in half and chuck one half in the small size collet of your dremel tool (preferably one with a speed control, set to slow). Dab a tiny bit of metal polish (Simichrome or similar) on the Q-tip bud and polish each tube pin, inside and out. Take another Q-tip and hit it with a little contact cleaner. Use that Q-tip to clean off the polish residue and dress the pins. Insert and remove the tube into/from the socket a few times - should feel pretty smooth if you have a good polish and lube on the pins.
I know this technique works, having used it many, many times over the years. And yet I was still delighted at how much more quiet the console is now. It cost a handful of Q-tips and a wee bit of polish and contact cleaner, takes a just a few minutes and made a remarkable improvement.