Bit late joining this but I have used ride on tyre sealant as a prevention for the last few years. Not seen it in action yet though but it does have a good reputation.
I have since decided to travel with a tyre plugging kit and to carry a mini compressor. This did save me when I was half way up the col d'allos this year and the valve failed in the rear tyre. With the compressor I was able to get the tyre to hold just enough pressure so I could complete the climb and get home that day.
Tyre plugger kit was the stop go one like here - http://www.ebay.co.uk/itm/3016628792...242%26_rdc%3D1
there are different size kits available with extra compressed air capsules
compressor is this one - http://www.ebay.co.uk/itm/CYCLEPUMP-...HFnlk6V4h0Fdpg
there are others around but I thought I would pay more for reliability.
and the sealant is this stuff - http://www.ride-on.com/
I asked if there was any difference between the car and motorcycle sealant and I was not convinced there was a difference apart from the price so I use the auto sealant in my car and bikes.
Hope that helps!