R57 - the way to succeed with using floated vacations hours is to post trips for pickup. On the N4 they show up 'below the line.' That's where you have more success vs relying on TTOT to drop trips. Above the line is company OT, 'below the line' is a pilot dropping a trip. Below the line pickups can be done before TTOT. It requires you to contact the owning pilot and he'll 'drop' the trip to you.
The better the trip, and the shorter it is(turns!!), the better odds of having someone pick up the trip. I've bid a month of turns and ended up not flying a single one. Dropped some, traded the others for different trips. It's a way to get time off when you can't hold a vacation in that month. You'll typically get a bunch of days off but it's harder to do if you're looking for a specific start and end date.
But even a blind squirrel gets lucky. Buddy dropped a trip over Christmas and used his floated vacation bank to pay for it. He was stunned that it allowed the drop but sometimes it happens.