I use them on all the pipes that I can, saves the stem and it's much more comfortable on the teeth if you need both hands. They do stretch and I find it easier if I wet it firts to put it on.
I just recently started using them on my vulcanite stems. It took some getting used to, but knowing my stems will stay in good shape was worth the adaptation.
I get my BJ Longs locally. But then again, they make them right here in town anyway, so... I got them when I first started out as it made clenching easier. Now I use them for stem protection as well. You do have to take them off occasionally to clean the stem underneath and wash them off.
-Jason
Yes! They work. I have sharp teeth and have ruined many a stem. They can be replaced but some craftsmen remove wood on the shank to match the stem and I have a Stanwell extra large Canadian the the replacement stem is a different shape then the original and it bugs me. I do not taste anything and they do not bother me.
I just recently tried them and I really like them. But you do have to take them off occasionally and clean underneath otherwise they can acquire a rather unpleasant taste
I do not use them as I prefer to hold my pipe, rather than clench.
My concern would be bacteria growth in such a warm, wet environment. I would recommend drying it after each use, and would clean it whenever I cleaned my pipe.