Lidl are selling tyre goo stuff again currently.

Last year when I had a nail in my tyre I shoved my old spare wheel and tyre that normally lost pressure in about 2 days, stuck a can of the lidl stuff in it and racked up about 500 miles trouble free before I got the other one plugged. Though this is using it as a cure after the fact, don't know how effective it would be in actually preventing a puncture.