Potato Gun Fuel ?

[gbu-36]

For those of you who have made potato guns, what has been the most reliable fuels for them ? Ive used butane. hairspray, starter fluid and alcohol thus far.
Hairspray gunks up the threads/inside of the gun.
Butane works ok, but doesnt seem to get the pressures Im looking for. (and its spensive)
alcohol from a spray bottle is ok, but getting the right fuel/air mixture seems a bit tricky
and starting fluid, oh holy jesus does it work, but quite honestly Im a bit worried about the pressure.

So, whats everyone else using for fuel in theirs ?
and if anyone wants Ill take pictures this weekend of my special ammo/tacticlol potato gun in action. and mebbe a write up on how I built it.

[Esophagus]

A writeup on how you built ti would be sweet. I've never actually made one, but I live in the perfect place to, and I really want to.

[torcher]

hydrogen is the most reliable and clean fuel ive ever used in one. after that would be Axe deodorant, then maybe aerosol tire shine.

[PirateJoe]

Compressed air

[gbu-36]

Sorry, no write up yet, Ive been super busy with work and family stuff (buying a house ! yay!). Ill work on everything during this week/weekend. Or Try to at least.