https://www.mcmaster.com/silicone-rubber-rod-stock/food-industry-high-temperature-silicone-rubber-rods/ link is for foodgrade silicone rod stock in a variety of diameters.
3 feet of 3/8" or 1/2" is about $10-$12 . It's not "crimped" so that hurdle will have to be vaulted.
Cut up gum rubber shoe soles from some old Wallabee's would be cheaper, but not food grade
I wish. No, I bought it from a reputable place and it came with a certificate signed by Tom Kapitany who is a Managing Director of Natural History Museum in Melbourne.
Ought to be able to clone that drill attachment for < $99. The ?silicone? "fingers" have me scratching my head for a secure mounting design, source for the fingers (or raw material)and/or a possible substitute.