Look closely at the picture I posted. What do you think I'm using as the insulator? It's the silicon tubing I'm talking about, and a replacement for what you guys are looking for.
Edit: my post might have sounded a wee bit snarky. Didn't mean it to come across that way.
Yes, I've been using the tubing as the insulator for quite a number of months. Never had to toss one out yet.
But it might take a couple of tries in the beginning before you get the hang of squeezing it in.