I recently removed some verdigris from a brass token with cayenne pepper hot sauce. I mixed in some cayenne power to thicken it into a paste and make it even more alkaline. As a paste I can control the application using a wood match stick to put just a small dab at the spot needed.
Um, I'm pretty sure the active principle in hot sauce is vinegar. Nothing "alkaline" about it. Just about guaranteed to trash your coin's surface...
I'm using old machine oil, it seems to be lightly acidic and the rust can be detached after some time. The coins surface becomes smoother and is somewhat preserved, but I don't know what kind of long time effect it will have. Also if gold coins form cupric acetate it calls into question the materials purity. Don't be so sure about that.
I believe the vinegar in cayenne hot sauce is over whelmed by the cayenne peppers and powder. The verdigris disolved in less than two minutes.
I don't clean any coins that are just melt value unless there is caked on gunk or I soak them in alcohol if they are from disgusting rolls. Today's junk may be tomorrow's collector coins.
what your coin really needs is a vibrator http://www.amazon.com/Lighthouse-Vibration-Coin-Cleaner-VBR1/dp/B002CJDGAI
And Ruben... when you're done vibrating your coins, you can give them a bath: http://www.amazon.com/Lighthouse-Cl...toys-and-games&ie=UTF8&qid=1346239078&sr=1-25
A good question. This coin doesn't appear to have much if any luster (hard to tell from a photo) and the toning is not really particularly pleasing. I'm not really sure if Tarnex would be the dip material of choice, but if you decide to do it, I would make little dips to remove the mottled toning, and be careful not to dammage the nice parts of the coin.
Ruben, sometimes I can't tell if you are kidding or not. I think this is the danger some people quote when a newbie reads your post and does buff his coins out with a cloth and Tarnex. On the other hand, I don't see what a quick dip in a good agent would do as harm to that coin.