GB -
I started out doing tray development. That was fine, but in spite of all the precautions, there was always a risk of scratching. Then a couple of years ago I discovered sloshers. Since then, not a single scratch. And they work for DBI.
A slosher is nothing more than a plastic cradle that holds the film emulsion-side-up as you process it in a tray. Each sheet of film is in its own compartment so that they can't move against each other to cause scratches. Agitation is by lifting alternate corners of the slosher and then dropping them back down into the solution. That forces the solution to flow through the holes in the bottom and sides, and around and over the individual sheets.
You can buy a commercial slosher, but I found that it was just as simple (and less expensive) to make my own. I used 1/4" plaxiglass from Home Despot - cut it on a table saw, and use a hole saw in an electric drill to drill circular holes in the bottom. Used plexiglass cement to put the pieces together (that's a bit hard to find - but a good glass shop should have it). My six-sheet slosher fits into an 11x14 tray and uses just 800ml of solution (I use HC-110, dilution H), and I also made a two-sheet version that fits in an 8x10 tray.