is this a special thing for tubeless? for tubed tires i use paper money. when i don't have that (very rare) i'll plan on looking around for some paper blowing in teh wind because we humans are dirty pigs paper is bound to be easy to find.
normally i'd agree with the duct tape. i'm using that on a tire that i crashed in for my trainer. it bulges a lot. would not be save to ride on.