I payed $35 for a 500 ml bottle 99.5% I doubt the head cleaning stuff would be of sufficient purity. Apparently it's not that good an idea to use pure IPA either; it's worth reading Dr Clays notes as what he says makes sense, he uses IPA, Windex and distilled water to dilute the stuff together with Kodak Photo Flo to minimise any streaking. Everything's filtered before mixing. I scaled down the measurements and made up a small batch only.
