Tinned wire in a one time pressed type fitting, grub screw connection in banana plug, for example, will compress over time and become loose. I have to tighten my banana plugs every time I handle them. Have a screwdriver there for the purpose. If the tinned part is under spring pressure like some speaker connections on both speakers and amps the movement of the solder is compensated by continuous pressure.
Deoxit kits have small brushes that would work well on female XLRs. Small brushes similar, different holder are available in oral care section of grocery/drug stores.
As to speaker wire, so many different ends hard to say but the Magneplanar connections would need to be released and retightenedat the bare minimum. Jim, I doubt you have the stock connectors on your speakers.
Power cords, plugs are easy to clean. One reason I like power conditioners for all but high power amps is because they have tight receptacles.
All the comments about operating controls, I pulled out the C-4 preamp to set up a good system with a new power amp and the vol and balance were both a bit noisy on first use in a couple years. Next day after exercising them, they were cleaned before the pre was set aside a couple years ago, they were quiet. Not much build up and easily moved with normal use of the control. I'll reevaluate to be sure before I go in or decide it is fine. Operating controls, breaking and remaking connections, scraping or abrasive cleaning of something like speaker wire or chemical cleaning will all work depending on the situation.
Hope folks report back the differences they notice after starting at the phono cartridge clips (maybe just rotate them a bit) through all the RCAs and XLRs to the speaker and antenna wire connections and finally at the AC or other power supply connections what improvements they hear.
While at the TT, might as well check azimuth, VTA, VTF, a/s and clean the cartridge with a soft brush to remove all the dust caught up in the cantilever assembly before giving the stylus a good cleaning.
