Most fishing stores sell surgical tubing,usually in 2-3 sizes..used for making weight snubbers for fishing for larger fish so the weight banging around won't lose the fish..or for river fishing for steelhead with 1/4" thick "dropper" lead.If the lead gets hung up on the rock,it releases that rather than losing the entire terminal gear and having to retie everything.Just slip in a new piece of lead to the rubber that is tied to a 3 way swivel so it hangs lower than the mainline.
You might also check the fishing area of wally's...
I tied up a half dozen of the tensioners out of surgical tubing and I think some exercise stuff..haven't tried them yet.
On the other hand..I got 3 feet of the good stuff at a garage sale the other day for a quarter!
The views and opinions expressed by this person are his own and not the general consensus of others on this website.Realityguy