Soft but safe material for tunnels?

[Alyxxx]

I kinda doubt it but is there anything that is soft like silicone, but safe to wear in fresh-ish stretches?

[stashapistachio]

Nope.
If its squishie or overly soft its going to be porous and not safe for fresh stretches.
I prefer glass > metal though. Its generally much more rounded and keeps heat a bit better.

[Alyxxx]

Thanks, that's what I thought but I figured it's worth a try!

Heat retention is good, so I think I will definitely go with glass then.