Erik
I don't know about "rot" or any other side effect of tire sealers, but I do have a totally reliable recommendation for tubeless sealer.
This is one that I learned about years ago when I watched Carl Decker set up his first non-UST tubeless tires.
Purchase a 16 oz. tub of liquid latex mold-builder from your local craft store for about $10.99. Mix any amount with water at roughly a 1:1 ratio (wiggle room on that as thicker sealant will seal larger holes, but thinner sealant will last longer). Use in the same amounts as you would regular Stan's fluid.
I haven't tried it in my cross tires yet, but I have had fantastic results with this mixture in MTB tubeless tires and non-tubeless conversions, and it is a fraction of the cost of any other tire sealant.
It's also water-based, so there should be little worry about caustic elements. I still wouldn't drink it, but it does seem less toxic than the other stuff.
-Erik
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