it was warm enough, and soft enough, that it collapsed, and fell from my hands, landing, edgewise, on the floor, where it crumpled into a wrinkled pile of paperweight.
That grit that has bonded with the vinyl grooves may well go away if the record is cleaned in an ultrasonic bath. My experience is that Ultrasound works great to remove excess dirt. My unit helped me salvage a great cart that I managed to wreck: An MC cart that I managed to land on an LP that I was processing with wood glue on the turntable. The glue surrounded the cantilever and rendered the cart useless. I kept that and years later I dipped it just slightly in the bath of the Ultrasound machine and the glue just melted and went away. Not even needed to heat the bath. I soaked the cart with 99% alcohol to remove any traces of water and it has been working again fine for years.
Precisely why I had high hopes for a format that had none of the physical problems. One that turned out having it's own unanticipated unintentional problems.
These records can not be salvaged, most likely its an Adiouquest mat made from sorbothane or something like it. The vinyl is blistered, had the same thing happen with much less time spent on the mat. The AQ mat was $90, I had two so the damage was twice as extensive. Some the blisters are faint and scattered with the records still playable, others not so much.