Originally Posted by
chas58
to prove a negative: I've gotten pinch flats in tubes with sealants. they don's seal. Centrifugal force pushes the sealant to the outside of the tire. There is no sealant on the inside. I even got a nail in a tire once - sealant plugged the tread area, but when the nail went deeper and punctured the tube on the other side (rim side), the tire went flat. Either way, it doesn't plug holes near the rim.
Sealant may not hurt in tubes - just be aware of its limitations.
I know this is pedantic, but you haven't proved that sealants don't seal pinch flats; you've only proven that sealant didn't seal some of
your pinch flats. Though your explanation of the physical forces seems reasonable.