Rickochet They can swell up and explode in seconds with an amazing force.
I wish I had had a video camera set up, all those years ago, when my brother and I were doing this. May have been before anyone was actually doing it. For some reason, the mouth of the grip was stuck tight, like it was glued on. I kept applying air; the more air, the larger the grip swelled. I just kept doing it, in short bursts, until the grip was about 2' long, and probably the diameter of a football(maybe larger). Finally, and lucky it did not knock me out, it exploded. Couldn't hear a thing for several minutes.
We did another, then after it was stretched considerably, let the air release. We then gripped the broom handle, without having to use solvent. Fun times. π