I once saw a demo of a foam sealant that could be used temporarily to fill cracks in a basement. The demo had a person shove the end of the can into a crack and

I once saw a demo of a foam sealant that could be used temporarily to fill cracks in a basement. The demo had a person shove the end of the can into a crack and then just press it and shot out and filled the crack. Once it absorbed enough water, it would start to dissolve and came out as a kind of slurry where it could easily be vacuumed and replaced with a proper sealant. It wasn't a permanent fix but was just there to buy some time. If they could implement a system like that in a car where the foam fills the cabin instantly and then water or sprinklers quickly dissolve it, something like Demolition Man could probably be a reality.