I don't know of any. Presumably one could be formulated that approximated or matched its working properties, but home-brewing the formula itself is likely difficult. It apparently contains several iminodiethanol compounds ("ammonia-based forms of sulfite and bromide" according to Anchell/Troop), and Polyvinylpyrrolidone. Not sure how easy these are to obtain. Gerald Kock, PE, Ian Grant could probably provide more info/guidance.