Gravityworks as in-line filter (not gravity filter)

I tried it sparingly a couple years ago with the older bigger version, and it was easy enough to pull water through by sucking. So, I can't see any obvious reason why it isn't used this way.

Also, but not sure if you can do this with the newer model, I cut off the rubberized protective shell and it didn't seem to leak or anything. Really not sure what that shell is there for, looks plenty tough without it, and the rubberized material seemed to almost double the weight.

Although, I don't use a bladder anymore, as I was either conserving too much water and would come to my next water source with plenty to spare or worse be sucking dry too soon. However, I'm thinking of rigging a straw version out of a newer one for a fill-on-the-go trail running bottle. So, I'd be interested in hearing any reasons why this is a potentially bad move… or if there is a cheaper but similar filtering alternative.

Thanks, Brandon.
When you mentioned removing the rubberized shell, were you referring the two soft gray "bumpers" on the ends (which I too removed)? Or something more?
Also, by rigging a straw version, are you thinking a straw that goes down into the bottle itself, sort of like the Evernew hydration tube? I've been contemplating the same. I saw some posts here where it seemed like people just shoved a length of the platy hose up into the bottom/inside of the platy twist-on hose. I've tried that experimentally, but have the impression that it might not stay put for long in real use. Maybe I'm wrong. I wonder if a regular drinking straw, with a bendy neck, could be used the same way. I'm guessing not, because what are the chances of being the exact right diameter to both fit and not leave a gap. I don't have a drinking straw sitting around to test this. Anyone?

With the older larger model, it had rubber all over it, so I took all the rubber off the outside of the filter. There wasn't any adhesive keeping it on, so I just took razor blade from one end to the other and it pretty much just pulled free. This left a plastic cylinder core with caps glued on the ends. I looked around for my old one to take a picture, but I kind of remember tossing it when thinking of all the foul water I had run through it. Probably still had a lot of life, but I didn't want to push it.

Not sure if the rubber'ish material on the new smaller one goes from end to end, and if it does, if it is even affixed the same way. So, if you're going to do anymore cutting, proceed with caution.

Originally with the on-the-go straw, I was thinking of doing it kind of like the 'Sawyer Water Treatment Filter Bottle', where the filter would sit at the bottom with some stiff straw attached coming out the top. Was hoping to test out one of those cheap sports bottles you get at an amusement park, but suspect those straws are too wide and too flimsy.