I regularly use a class of balloon known as a Screaming Tiger Tail - a very long balloon, the purpose of which is to fly around making a lot of noise. It's a very noisy balloon anyway, and very versatile - inflated one may coax all manner of frequencies from sub-bass to dog-bothering screeches simply by caressing it with moistened finger tips. In performances of free-improvisation I'll used one with a microphone, a mixer, and a diversity of effects pedals; basically the same set-up I use for my Jew's Harps. See Here for a picture taken a the Red Deer in Sheffield last year. Visually, they're pretty impressive too.

I've used one to accompany The Housecarpenter in such a context, but never in a folk club, fearing folkies would be less willing to accept a balloon as a musical instrument (far less the sounds as music, traditional or otherwise) than free-improvisers are to accept traditional ballads as a valid part of musical performance.      

Another use for the ever-versatile Screaming Tiger Tail comes from the fact that, unlike regular balloons, the closed end of the tube is knotted, with the knot being covered by a fetching little rubber condom affair. This knot can be undone and the mouthpiece of a Practise Chanter inserted therein. With but few modifications (such as fixing up the blown end of the balloon with a simple non-return valve so as you can keep it inflated) you've got yourself a very handsome bagpipe.