OP, did you ever have any luck with those wheels.
I did get IronX Snow Soap and have been playing around with it straight on a set of bad wheels. My own unfortunately.
Same deal with a spent pad and my wife did not say anything about it grinding. I thought the wheels were getting extra dirty and I had been neglected them for a while. If she is home, the kids are home and it makes getting anything done to the car a PITA. Last time I changed them I put aggressive pads on it, and will never do that again either.
The straight Snow Soap works but its slow. Its taken me three days of repeated applications and basically letting dwell most of the day to get them cleaned up. But it's done it with little to no scrubbing. I did the no scrubbing because I wanted to see if it would do it just by its reaction.