Well, it's only 54 base damage, and I'm not sure what that works out to at +7 sharp but it's going to take quite a few swings to kill a jailer and the poison isn't really going to help. If it stunlocks them the whole time it might be fine to kill one at a time, but realize that later on you have to deal with multiple jailers at once. If it takes you several seconds to kill one, you're going to have a bad time. The hp drain itself won't actually kill you, but the moveset on their soldering iron is retarded because it hits on the first frame or two of the animation and that's game over.
Semi-related, I'm finding Sharp gems to be basically worthless. I had 40 dex long before 40 str, so I assumed that putting Sharp on one of my katanas would be a good idea. Nope, even weapons hugely skewed towards dex builds gain practically nothing from sharp. It would have been like 5-7 AR higher than when it wasn't infused at all, which is a goddamn joke compared to what heavy and refined gems do for 40 str or 40/40 builds.
Anyway, I'd suggest something with more of a punch than a dagger. Uchigatana is ideal if you're pumping dex, since it will kill jailers quickly and the R2 is a stab for the caged assholes. I'm pretty sure I used a black blade for my first clear of the place; the only real difference between it and uchi is that you have to R2-R2 to get a stab. I *think* the first R2 slash could knock jailers down, but don't quote me on that.