R,
I guess, at least from my point of view, that the question qwas one more of curiosity. At least as far a any code or spec compliance is concerned I don't beleive there is any alternatives out there. But it leads to the question: is purging of your product actually necessary to its application. I'm just curious. HT of course oxidizes surfaces but in most instances it doesn't matter or the material will undergo a final coating that renders the oxidation irrelevent. For example blasting, wheelabrator, etc., processes, which are cheaper than purging HT's.