I'd been interested in trying contact cleaner. Not the kind that makes you see better, but the one for cleaning/lubricating electrical contacts. I'd done so on the basis of manufacturers' claims of improvements to everything audible and I figured that for a few dollars my gear and I wouldn't notice it if I'd thrown my money away. At very least it seemed a sensible preventative measure, a bit like a car service. So I got some stuff recommended by Bill, being a can of spray (non-CFC propellant if that bothers you) with the usual thin plastic tube to finely direct the spray. My gear, if it's useful to know, is ELAC 249s, Bill's Lucien amp, Denon S10 CD player, 1974 vintage Linn.
I did as Bill directed ..... unplugged the gear from the wall, took out each interconnect and sprayed (a bit like "drenched") the male and female bits (RCA, XLR, Speakon, speaker connections, power cords) and reconnected them while wet as I did each one.
I'm crap at using hi-fi descriptions like "sweeter, gorgeous, mouth-wateringly even more sublime highs", "fulsome, buxom mids", "deeper than the deepest sea bass", etc. The best you are going to get from me is this:
If you even think of upgrading anything in your system, you really must clean the interconnects with stuff like this, listen and then decide if you really needed that upgrade or perhaps leave it till another day. You will be more than just a little surprised at what you hear .... Damn, it's really worth doing! The "investment" in time (15 minutes) and money (very little) is so small that you really have nothing to lose. And I tell you, the improvement is really there. Trust me, I'm not a lawyer or a politician.