I've never used the preventative stuff, I don't carry a spare wheel just two cans of tyre seal. The only puncture I have ever had came from rubbing wheels with another car, it tore the valve off so sealer was useless. Go figure.
I used Slime when I went to beadlocks, I'll never go back to tubes. I finished Warialda with a hole in the tyre you could put your finger through, and the tyre didn't deflate until it was sitting in parc ferme.
