Yeah, I just shave a bit off the end as a matter of course, while I'm gutting them.
I just realized that someone may not know what I mean by "gutting" a cartridge, since that's just my own description. Basically, you just remove the inserts and cut or drill the bottom out of the
juice reservoir. You end up with what looks like a (mostly) empty tube, that you can drip straight through without removing. It's just a mouthpiece at that point.