My old dealer (who I miss dearly), back when I was new to this hobby, recommended a once or twice a year chore of going through all a system’s contacts (RCA, XLR, spades, bananas) with deoxit. I don’t believe he used Caig’s (it was a cheaper brand), but I forget what now. Caig deoxit is certainly good if that’s what you have.
It’s a good idea - I’ve certainly seen my share of L/R channel imbalance issues from poor contact quality gremlins. However for most of the past several years, I’ve swapped component & cables frequently enough that the wiping action (make & break a connection a few times) probably kept most of my contacts clean enough on its own.
Rhodium, gold, and platinum plated contacts seem pretty stable. These probably need far less cleaning? In the quest of audiophile nervosa, we now have pure copper and silver contacts, which are a real bear to keep clean! Audioquest claims the eventual blackening of their silver-plated contacts (pure copper underneath) is not a problem because silver-oxide is such a good conductor (it is). But I question that! Is that blackening really just oxide, or is it (more likely) silver tarnish (silver sulfide), which is NOT a very good conductor? Anyways, keeping your contacts clean of oxides and tarnish is always a good choice.
Vintage tubes with steel pins often look like a blackened mess, and I wonder about them. They usually seem to work fine, at least. Vintage tubes with gold pins held up well, and usually look great. VTS (Andy Bowman) thoroughly treats his tube's pins so they look exceptionally clean, gleaming steel. But I wonder if this changes the sound!