Hard to beat Markphd's original response. Nothing wrong with also doing a little wiping with fine emery & cleaning if desired. Away from the audiophile world you are not likely to find high cost fairy goop in critical signal paths (I think the reason for this is that testing and calibration instruments are greatly lacking in imagination). You will find some relatively low dollar goop used to help prevent a hot joint where fairly high currents are involved.
Are contact treatments worth the money?
I have been reading some of the claims regarding the benefits of applying contact paste, liquids, etc. to all my connections. It sounds appealing but would like to know your experience with such products. Prices range from $35 to hundreds.