"My "longevity" issue is with tubes of caulk or silicone sealant..
They never seem to last more than a week after I open 'em, regardless
of the measures I take to seal 'em up. "

In this case I don't have a problem with caulks...I just wrap a piece
of tape around the open tip and put in on a shelf which is subject to
normal indoor temperatures and humidity.

TMT