Can't help with the "wet" part but heres what I did and what I do now.
I have a Toro Z28 and a 5HP trac vac leaf vac with cart.
When I first got both I pulled the trac vac over the leaves and cut and vacuumed at the same time. I mow a little less than 10 acres with varying degrees of trees. I dumped and dumped and dumped the trac vac. Now, I cut first, clean up second. First I mow around all the trees then mow over the leaves a couple of times to cut them up as small as possible, (yes I have mulch blades.) Now I only have to empty the trac vac a couple of times. Much less of a hassle with the number of bails of leaves coming out of the vac and what to do with them. It's also a lot faster not pulling the trailer around the trees.