well i know you can buy some made by Holts, this comes in a blue/ white can.
i used some a few years ago when i got a flat in the middle of knowhere, dark, raining (always the case) and when i looked in the toolkit for the first time - NO JACK.....
i stopped a passing car and he had some of this in his boot (maybe thats why he walked with a limp
) and luckily he sold me the can. The next day i went to get the puncture fixed and was told that by using foam there wasnt anyway of finding the hole unless it was noticeable from the outside.