Rich hit it.
Generallyspeaking, using the very least amount of whatever you are using as a contact enhancer need to be the rule.
On DeOxit products, they use a solvent/treatment that has a very high edge to edge affinity for the molecular structure. What this means is that they want to spread out until the are about one molecule thick, The molecules were are talking about here are reasonably small and can still cause a problem because of migration to other surfaces. That is one of the reasons I don't use them unless there is absolutely a proper application. ProGold ends up gooey after a few months. After using it the first time, I was disappointed in application.
For cleaning parts and pieces before treatment I use Perfprmance Plus R/C Car Cleaner. Enviro friendly and very effective. It comes in a 24oz (I think) spray can and lasts forever.
Now, for the adventurous and kinda dumb prople like me that tend to stretch the envelop of "goodness", I suggest 30% hydrogen peroxide as a very effective cleaner. It is, however somewhat dangerous due to it being such a strong antagonist to organics... like your fingers, eyes, nose, Mr. Winkie. It will burn exposed flesh quickly.
Uhm, how about this? The MSDS -
https://rsc.aux.eng.ufl.edu/_files/msds/302.pdfI'm just trying to get everything out in front of the fact that it is a tremendous electrical contact cleaner. It'll strip the schmutz out of the base metal and pretty much leave everything else alone. If concerned a rinse or swabbing with
DeIONIZED water, not distilled, will get everything back into envirionmental balance and we won't go spinning off into the sun. A small bottle will last years.
Another word of caution. It will rest steel in a heartbeat if left unattended.