Onion Bag Bin
It seems in a flow through there is never enough of a hole in the bottom for the vermicompost to flow. It is also difficult to get enough air into the bin. Maybe the Costco size onion bag would make a bin. It is used to carrying heavy weight. It could be hung up over a barrel. The barrel could actually double as a constant brew. Every week the bin could be harvested by dunking it a few times in the barrel. Then feed bin. The worm in just gets so heavy that it is difficult to harvest.