That is the first time have EVER heard of anything actually getting rid of the "green crusties" ! Even it you have wait a week and and re-apply !!
It doesn't make them disappear, BUT it does make them let go of the copper. If you've dealt with the "green crusties", you know how they normally require abrasive action to get to good conductive metal, and how no amount of spraying CRC (which is a very good cleaner BTW) will do anything to remove them.
Well, if you give DeOxit enough time to work its way down to the good metal (this can take weeks, if it is bad enough), what is left behind of the green is what I would describe as a foamy scum that will wash off with just a shot of spray cleaner.
My first test of DeOxit was on a solid copper (pre-1982) penny sitting on my desk. It started out about as dark brown as one can get (like a well weathered bronze sculpture). I put a small drop of DeOxit sitting on a spot on it, and left it to sit. Around a month later, I looked back, and the drop was ringed by the green foamy scum. A quick wipe with a piece of TP (one might call the TP at work kind of abrasive, but copper is more resistant to abrasion than my rear end...) left nothing green behind. All the green came off on the TP, and the place where the drop was, had greatly lightened in color, and had a nice metallic twinkle to it.
I've since used it on many copper, silver plated, and more exotic alloys with great success.
For my part, I would suggest being very careful with mechanical means of removing corrosion from contacts. It can lead to loose fitting contacts that bring up new problems.
To be fair, there are plenty of chemicals that will remove the green crusties. An acid dip will for sure too (and that can be a valid method, IF you can be sure that no acid will be wicked into places where it cannot be neutralized following the dip). What I find special about DeOxit is that it selectively removes the oxidation, without slowly destroying the copper underneath.
