I'm not sure where you're located. At the labs I've worked at we always bought it at a photo supply company in town. I did find this link to it at Adorama
http://www.adorama.com/CHPEC12.html?...59362032266518
The only suggestion I can give you about using it, is to spray it on a piece of soft cloth of some kind, then wipe your photo. Don't spray it directly on the photo itself.
It is a miracle cleaner. I love the stuff!! If you can take anything off a photo before doing your retouching, it's less time on the computer for you. And besides it makes you look llike a genius to any clients you have.