I forgot to mention how the sealants work. So no matter the formulation, rubber based, latex based or fiber based they all work under the same principles. Under normal conditions they are liquids of course. If you expose any of those compounds to the combination of air and high pressure and they become solids. Their behavior is like that of a non-newtonian fluid. So under normal circumstances they are liquids but under stress, high pressure, impacts, quick change in pressure, they become solids. The major difference between the tire sealants and a true non-newtonian fluid is that the sealants don't revert back to liquids once the pressure is gone. Tire sealants actually permanently solidify once they are exposed to the high pressure from a air escaping from a hole and the pressure of being pushed into it. Michelin uses a sealant compound that is rubber based so it forms a permanent rubber plug in the hole from the puncture. Like I mentioned above the plug could be knocked out, like any other plug you would put into a tire. It just isn't very likely due to the impact required to do so. Even if it did happen more sealant would form another plug.