Hm, the best way I can describe the water in the blade technique is like Hisagi's fight against the crab like guy who shot high pressure water out of his claw? if you remember him it's similar but it's almost like the blade is hollow and the water shoots out from inside the blade.
Otherwise take a look at this - http://www.youtube.com/watch?v=Sa_NC-_fvKs
It's a video of a 'Wasp Knife' a normal knife but when activated releases compressed air through the blade which as you see almost makes the watermelon pop, it would be similar, shooting high pressure water into a cut. Almost like a bullet that shatters when it hits, it would cut everything up inside.
On the Osmosis trick I don't intend for it to be super quick. Especially at un-ranked level. It's more of a slowly wear people down kind of thing, either through overhydration or dehydration. I'm not going to use it to terrible effect but I also don't want it to be just cast aside, I would most likely use it as a way of slowing others down or something similar.