Yep hydrogen peroxide has worked the best for me. I just dumped a whole rack in a bowl with a fresh bottle. Will let them sit all day and maybe overnight. Looks like it didn’t bother the HS either. Mine HS was gone on my tester chip due to using other chemicals before trying hydrogen peroxide. More to come….
It kinda looked like fecal matter - or “dirt“ - had sprayed onto/settled into the chips, and with the bubbling reaction from the hydrogen peroxide it may seem more likely so. Good cleanup though!
I would put a poop emoji label on them and call it a day!