Stewart recommends surgical tubing, if you can’t use the tubing from your water purification unit. You can use it for a tourniquet too, and other uses, I forget them.
Since you can see through it, just stop sucking when you see fuel an inch from your nose. You could carry a rubber squeeze bulb, that would be a luxury item and in your BOB, every ounce matters. Personally I love the taste of gasoline in the morning, and belching flame.
Personally I love the taste of gasoline in the morning, and belching flame.
and for the visual. :)