The stuff that oozed out is all the grease and accumulated road grime, and trapped impurities in the metal when it was formed. It seems to me they don't outgas their customers' parts first before blasting and coating (a typical rookie inexperience issue). Chances are good that the two prior hearings also brought similar crap to the surface and that's probably what the contamination was from to start with. I hate to see anybody get ripped off; at least you got a partial refund.