you had got it right buddy..........
"isopropyl" is the best solution.But remember one good technique that i learnt about it... isopropyl evaporates quickly when poured directly on the board...
instead what u do is take a very small piece of cloth or cotton bud(ear bud); dip in isopropyl and then clean it.... dont forget to close the bottle cap.... also i generally prefer to take small amount of isopropyl in a seperate small bottle so that u can dip the same old bud again and also prevent wastage....
also it helps avoid accidents like dropping the bottle and damaging other things...
Caution: Use gloves and face mask to be on a safer side...(its not that harmfull,but u must take precautions)
Also if while using it u feel burning sensation in ur nose or eyes, stop its use immediately. I have learnt that some people are allergic to it but it is never noticed....(actully its Vapor causes it)