I've seen those bowls a few times and they definitely piqued my interest. Don't get me wrong I love my full melt bubble but messing with bags can be a pain. Making bubble is no fun.
skip all the hassle and buy yourself some dry sifting screens from pocono or the likes. Easier to make, less tools and equipment required, no room for error drying like with water hash(I see poor drying and separation all the time online) and you end up with a superior product for like 1/10th of the price. Dry sift is the future.
the original true bubble bags are the same way basically water only flows down when you get to the last few screens on a big bubble bag run you sit and wait and wait and wait for the last two bags to drain out.. the newer style bags are mesh all around so they drain easier. I'm still a bubble bag fan though i haven't used the newer all mesh ones
No need to wait man just jerk the bag up and down a couple times and it drains in mere seconds. Bubbleman demonstrates this on his videos all the time.