i used an old bong tube myself with a pice of fabric jubaliee cliped to one end filled with corsely crushed dry leaf matter plastic lid on gas in end useing the lighter filler tip as the adapter to fill the tube with gas, an only a couple ounce at a time, i wouldnt know but id take a guess that you need to use a longer tube of the same diamiter to acheve good saturation and extraction, obv you know how dangerous it can be as youve done it befor problem is the larger diamiter the tube the more gas you need i wouldnt think length is an issue unless going more than a mtrt, so more danger its hevier than air so you end up with it sitting on the floor never do it inside be extereamly care full when it comes to sorces of ignition,
any ways it would be hard to fill more than 1 tube at a time from the same butain input so maybe a length of drain pipe is needed no more than six inch diamiter i would guess trial and error on howmuch gas you need, i used about 5 pureist butain lighter refils just on the bong tube thats 3 trips to diffrent shops, dun know if this hellps m8
