I use lavatanks made by joboyusmc exclusively. Here's a pic so you can see what I'm referring to:
Yes, I use the top cap to force juice into the carto. I used to slot them, then I got a punch and punched 1-2 holes. Now I punch 4 in every carto I use. I punch two at the bottom, opposite each other and two at the top, staggered from the two at the bottom. My punch allows two full screw turns after punching through the metal. 2 full turns of 4 holes will flood the carto, so I've been going with about 1/2 a turn after punching through and it's been working great.
Yes, I use the top cap to force juice into the carto. I used to slot them, then I got a punch and punched 1-2 holes. Now I punch 4 in every carto I use. I punch two at the bottom, opposite each other and two at the top, staggered from the two at the bottom. My punch allows two full screw turns after punching through the metal. 2 full turns of 4 holes will flood the carto, so I've been going with about 1/2 a turn after punching through and it's been working great.