So, does noone drip it into the male threaded hole? (the brass peice that screws into the battery?) I saw that as 'how to fill' them on a few websites that sell them-
Actually MistressNomad recommends that in her excellent videos for newbies and it was the only way I could refill those cartos on my horrible first mall kit. If it doesn't have the nice soft caps like the Boges and it's working for you, keep doing it.