Hey Rob (@robertross),
Since Matthew is not responding I will try to answer your question. Yes it is the stuff you should use for breaking up clay-rich rocks but you might have to dissolute it in Isopropanol to get a 75% solution. I guess there might be a chance to order Rewoquat but not in small amounts. The easiest way is to contact the German headquarter and ask. If they just ship large amounts then we probably can order and split it for all parties interested.
best
Ronny