Well you're doing all that I could really recommend which is rubbing alcohol and QTips (cotton wool buds as we call in over here in the UK). You may wish to try a lint-free cloth. Just be careful you don't bend or break any of the pins on the CPU or in the motherboard and make sure you don't bend or damage anything on the motherboard itself.
If it were me I'd clean it all off before booting my system, I wouldn't want to take the risk personally. You can perhaps try a more concentrated isopropyl solution - 99% if you can this may help.
I doubt very much you would be able to return the board since it was your fault. Try your best to clean it and hope for the best. And don't apply so much next time