It depends how the cart was put together. All carts have slightly different amount of filler. After washing them out and blow drying them for 40-60 seconds, I pop the mouth cap off and fill them from the battery side. Yup, on the BATTERY side. I get more
juice in that way and the inner padding gets soaked first (this is where it vapes the
juice). I get 30-40 drops. Yes, 30-40. Look at the filler once in a while (at 15 drops, 25, 30,33, etc.) until you see it get soaked. In between, I get a straightened paper clip and put it though the battery end all the way up the opened top. I then grab the end piece and slowly swirl it around so that the inner padding soaks the
juice. I've been doing this routine for the past 10 carts. It works great.
The hardest part is knowing when to stop drippin' (gauging the fullness of the filler). Once in a while I get a really misaligned and misassembled cart. Inner padding is all jumbled up and is not wrapped properly around the center hole and tube.
Hope this helps.