Yep, that method has been discussed in the past using
a different type of cleaning solution, but effectively it does the same thing. I use the latter myself.
What is worth pointing out, however, is that if using these cleaning compounds, you need to be very meticulous removing any leftover residue from the compound itself. They tend to be "chalky", leaving an off-white film of crap on the pins which has to be cleaned off using water or isopropyl alcohol.
I have received a couple carts and products from people over the years where these compounds have been used on cart connectors but water/etc. had never been used to clean off the residue.
For carts or things which can't be easily opened (ex. Famicom carts, or NES carts where the individual lacks the proper security bit), just use a wet Q-tip, followed by a dry Q-tip.
And also for readers: you don't need to use very much compound. Half of a US dime is enough for both sides, IMO.
One thing I do worry about with these compounds is their harshness. Most of the time when cleaning the edge connectors, the cleaning device (rag, Q-tip, etc.) becomes slightly grey which is expected (mix of the compound and the oxidised tarnish from the edge connectors). However I've cleaned a couple carts where the results were thick and black, not grey, and upon examination of the edge connectors, found that some of the gold metal had actually disappeared (i.e. just bare off-white PCB was exposed). It's hard for me to know if this was caused by the compound or not, but I still mention it as a caution. I think this is what Pasky meant when he said "Don't suggest doing this unless you have a cart that isn't working very well as you're removing the original coating" -- I agree completely.
