I should note that I reference latex tubing in the write-up. I have also used silicone tubing for hi-starts. It is hard to compare the two unless you have two pieces, side by side of the same dimensions, but I would say both are valid. I think silicone tubing is used more in the exercise machine world. I have seen it for sale on e-bay and Hobby King.
When buying tubing make sure you know if it is a single solid piece. Sometimes they offer 100 feet of tubing but it is 100 feet of random lengths. Two pieces would be OK and might even work well to have a short and long. You can join them. I would not want to join 10 pieces to make a hi-start, but it might work.
However my default is still Latex.
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