I order SSV tubing direct from 7th floor, and I also use a US Plastic food/beverage grade silicone.... and also a medical grade one.
I opt for the official SSV/DBV tubing for my own personal use EVERY time.
It is a specially made extra soft silicone, ordered by 7th floor. They had to order enough of it to go around the earth 9 times to have the stuff manufactured.
Here you see one of the Silicon-Tygon SSV/DBV drawers in my Tubing/Whip replacement/repair station.
These are:
Tygon Beverage Tubing 3/8" I.D. 1/2" O.D. and 1/16" wall
Tygon Medical Tubing 3/8" I.D. 1/2" O.D. and 1/16" wall
and SSV Tubing.
I have tested each, and the SSV tubing cleans the easiest, gets less yellowed with time, smells less, is softer and does not harden.
I actually have my original SSV tubing on my main SSV unit. It is 2 years old, and has been cleaned weekly with Iso, followed by dish soap and hot water.
You will see that the "wand" end is yellowed from daily use over two years, but it is clean.
I have in that two years thrown away, and watched crack or destroy before my eyes every other kind of tubing including medical grade tubing (which I use to repair other peoples stuff when they request it.. but it sits in my home unused!).
So... the bottom line is-
In my opinion... if you want the safest and best whip for vaping... the longest lasting, easiest to keep..
SSV/DBV official tubing is best, and I own and have used them all.