DeoxIT on tube pins

Another option...regarding magic eraser....the substance/product that florists use in their arrangements??

As stated in a post above, just plug in/out a few times.  The risk/reward of contact cleaners isn't worth any potential sonic improvement.

Some basic contact cleaner that quickly evaporates without residue (unlike DeOxit) should be safe. I’d spray it on the Magic Eraser pad and then dip the pins. Note that you don’t need a near-mirror finish on the pins like you find with new-production tubes. Just clean them until they no longer appear dull. The further abrasion from installation in the tube sockets will make for a very sufficient contact.

Deoxit is more than a cleaner. It “conditions” the metal surfaces. The problem is folks sometimes don’t wipe it off sufficiently after applying. Or are too aggressive in the application. Also, these cleaners and conditioners are nice but real contact enhances are head and shoulders above them, you know, the silver bearing stuff and graphene. The best bang for the buck is clean all contacts in the house with alcohol. Put your backs into, boys!

for tube pins.. use Caig Gold Dx2/ different than the regular gold 100L The Dx2 is good up to 500C temperature!!! cost a lot more though.   like   $99.                     
https://www.amazon.com/DeoxITGOLD-Liquid-brush-appl-Tracer/dp/B003D8GUAA