Do you have a Walmart near you? I bought a large can of cleaner for around $1.98. HOW CHEAP IS THAT!!! What I bought is the following:
CRC QD Electronic Cleaner. It is a spray and a generous amount of 11 oz. I think it is worth a try. It certainly didn't hurt my keyboard and I have not had any problem with the key playing loud by barely touching it. It responds, touch sensitive wise just like the rest of the keys. Good luck if you decide to try it.