I've been using MG Chemicals ElecroSolve for years now.
Prior to that I used Cramolin (sp?) which may have later developed into Deoxit by Caig and for a while I used Kontak cleaner from Europe.
I've been told that alcohol can damage the gold plating on tube pins, so I do not use it on anything gold plated.
I've also read (here) that high percentage isopropyl alcohol most likely contains carcinogens due to the manufacturing process so I switched to 91% to use in my DIY vinyl cleaning solution.
The MG cleaner is readily available on the WWW.
Sorry for more run-ons than usual, but I'm in a hurry and out the door.
https://mgchemicals.com/products/electronics-maintenance/contact-cleaners/contact-cleaner-spray/
DeKay