Last night i finally give this a go per the original instructions with a straw. I used a 1/4" Diameter straw and it basicly hugs the inside of the cart. For the cap i used a hole in the middle and then just the star pattern.
With my cut open atty and cart i used as a model, i made sure the straw and cap were at the perfect level so the bridge just slightly opens the plug.
Yeah it leaks a little.. BUT, works awesomely for HV! And thats currently what i need it for.
Also.. sometimes i had to snap my wrist downward to get the juice to flow if it seemed dry and that worked ok. May just be cause of the thick juice i was using.
So its got some flaws that need to be addressed.. but its got some obvious promise.