Things to do with old filters?

[Gedda206]

So my father uses Krave e-Cigs. I've found 46 used disposable cartridges for them and have them in 4 of the 26 cases they're sold in... But I don't know what to do with them. I've also put the rubber plugs on them as they originally are. Any crafty ideas?
P.S.,
I've found that the 21st Century Smoke filters can attach to the Krave filters, but it doesn't have a good seal unless you put a broken rubber sealer thing around where you connect it.
Thanks!
-Certainly Not The Muffin Man (Tell them you DON'T know me!)

 

[FantWriter]

If it was me, I'd tear one (or more) apart to see how they're put together and then develop a strategy for refilling them.

I don't know what the Krave are like, but the two proprietary ones I investigated had the mouthpiece glued in to prevent refilling. All it took was cutting those out and replacing them with drip tips.