Any hole that makes you tire go flat "quickly" will not be fixable with fix-a-flat. It will just blow out through the hole in the tube, and might even make the tube hole bigger.
I have heard mixed things about this stuff, and can't recall ever hearing about true success on a tube puncture... but I haven't looked hard either.
http://www.ride-on.com/motorcycle-formula-mot.htmlIf you use that stuff, it might seal up enough to get you to the next town.
A 12volt compressor might be a good idea too.
And, a good Auto Club card is priceless!!