I use a double 3mm silica build. When I rebuild one again, I'll put up a few photo's - it's a bit hard to describe by text but basically I have the bottom ones coming out into the tank, cut with about 2mm poking out. A lot of people cut them right on the edge but when they get wet, they shrink slightly and that leaves a bit of a gap which can cause flooding. The top wicks I leave long and are kept inside the well to soak up the juice, which again prevents leaking and dry hits.
The trick when filling is to not only close the air hole tight but also to use a needle tip to fill it, making sure that there's a gap in the fill hole. As the Fogger works on a vacume, if you fill straight from the bottle it's really easy to create a seal with the end of the bottle and this forces the juice through the air holes - not good.
I've never had a single problem with leaks or dry hits since I've done it this way and they're vaping better than my Kayfuns.
Stick with them, they're worth the time invested in trying to get them right.
SB.
