Cleaning agents?

I don't think I have the system to notice substantial improvement, but I think audioquest cleaner via amusicdirect is a good deal, around $10. AQ's wrench is about the best $8 you can spend, too.

Ohlala is right. Audioquest is a good cleaner. You might want to follow with TC-2 contact enhancer by Torumat. Also try TPC wipes from Roger Skoff of XLO co. It is a cleaner/contact enhancer in one. They are individually sealed and go for a buck a wipe. It does make an audible difference. Happy Listening! John

The audioquest stuff works good for cleaning really dirty connections, but I think it is more than 10 bones. The xlo wipes are the ones that I have found to make the most audible difference, and the progold seems to be not quite as good. The audioquest, I find, doesn't sound as good as either. I haven't tried the sumiko contact but I am curios.
I would not be without contact cleaner. The difference a clean vs. dirty connection is important for sound quality.

I'll take the Basement Challenge :)

http://www.amusicdirect.com/products/detail.asp?sku=AAQUC01

And that includes pipe cleaners! Sweet!

See recent M. Fremer column in Stereophiile re use of a German metal cleaner called "Flitz." I've had amazing success using this stuff (available at well-stocked hardware stores) followed by use of contact cleaner (or just alcohol).

I second Dopogue's recommendation. On the basis of a post here on Audiogon I went to the Flitz website and ordered a sample for $5.00 shipping and handling (handling must be $4.20, because shipping was 80 cents; but I digress). It arrived (very small tube), I used it on everything (including those IEC inner prongs - stiff and bristly pipe cleaners needed here), and the sound was vastly improved. Airier, less sibilant, more coherent. In short, magical. I couldn't believe (a) the improvement; (b) all the black gunk you'll remove from apparently clean connections. The speaker spades, in particular, looked all shiny and new. BTW, I used up less than a fourth of that small tube.