I just did it with the top of a Pentosin bottle, but in order to get it to work (reliably) you have to pour a little bit out of the container as you open them and before you put the modified cap on or the short tube can be submerged. It isn't to bad though, you just pour the little bit off in to an old empty container until it's full enough to pump on


Yea, you can't fill a vessel full and get it done in one push per say, but it's easy to change a cap and you have to open each container individually anyway.


Can also do it for gear oil, etc, etc, just modify and save "that" particular cap.