A most impressive fuel for such WMD is MEK (Methyl Ethyl Ketone (2-Butanone)). Produced some fabulous results from a big bertha contstructed from catering-sized bean cans lashed together in Deci back in 93. A plentiful supply of said propellant could be obtained from the sqn engineers (in those days at least).
A little googling reveals it not to be a particularly nice substance:
http://www.epa.gov/ttn/atw/hlthef/methylet.html
so do your own research. Of course researching rather ruins the spontaneity of such events, but it's a litigious world out there.................