Mine looked similar. Had slimmed them because of all the honey locust with 3” thorns on my property. I had even plugged a couple holes that were too big for the slime.I put slime in tires not long after I got it as a preventive measure some 15 odd years ago and used everything from bicycle pumps to compressors to fill tires so there's no telling what else is in there with the slime. I'm just glad I talked myself into buying more shoes for her instead of just pulling valve stems and filling old ones with expanding foam.
