Posted: Wed Jun 20, 2007 8:42 pm
If you buy one of those cheapish metal 500 ml syringes to remove the stuff in the first place you should just be able to reverse the process 8 times to get 4l in?
A forum for Bongo fans and owners
https://www.igmaynard.co.uk/bongo/forum/
https://www.igmaynard.co.uk/bongo/forum/viewtopic.php?t=12242