I've never heard of TSP 90. A quick lookup says its a cleaner. I've always just used straight Oxiclean for my kegs. buckets etc with good results. Aside from knocking down the foam which isn't an issue for me,Is there a reason to mix this with Oxiclean. Does it turn Oxiclean into some sort of super cleaner? I also read its near impossible to get off glass. I wash/dump my stuff in a tub with glass shower doors and it always splashes up on the glass. Definitely don't want to be ruining my doors. Would this be an issue??