Asking anybody that has a lot of experience using the Candle-Flex molds, how long do they last? Are you getting dozens of pours or hundreds? In particular I'm thinking of the taper molds. Does the constant rewicking wear the silicon out? I've noticed on two of mine that the silicone used to hold the wick tightly in place after securing the wick at the other end but lately not so much. I may have to clamp the wick where it comes through the silicone to keep things on the straight and narrow. Comments?