Hmmm.. I actually just started using it today, so not ready to give up just yet, lol!
I haven't had any flooding all day and I put about 20 drops in. You're using a 510? If not, I'd have to defer to someone else's experience.
The method I used a saw on a video here: I used 1/2 piece. Folded it in half widthwise. Folded the top down two more times, then folded it lengthwise in a roll. Then, cut the unfolded end with one cut from the bottom up to the double fold. Once in the cart, I spread open the roll, to make a bit of a hole in the middle. Did you see that video?
I think that the double fold at the top and the way the cut bottom flares out may help hold the liquid in the cart until needed. I actually took a draw and pulled the cart off really fast and could see the liquid had pulled to the top and then seeped back down again as I watched. It's not refilling really well though. I'm only topping off 3-4 drops instead of a complete refill - so it's not wicking dry like expected.
If it's not working, have you tried the straw
mod? That has been pretty consistant for me, but I've always been willing to try need cart
mods to see what is better.