Foamy Inflation Solution

A lot of cars these days don't have a spare wheel - they have a canister of something you squirt into the valve, so the above is not as insane as it seems :~)

Although I am not quite sure if the foam in a fire extinguisher is the same stuff as in a foam canister in a car. So I cannot rule out the possibility the stuff in a fire extinguisher is not causing more damage than you already got. The foam in a repair kit also hardens up. The foam to put out fire does overall not...

Well, at least the tyre shouldn't catch fire :~)