To begin tray developing, I would suggest starting with 6, no more. Rotate thru all 6 in 30 reconds, that way, each film is "agitated" for about 5 seconds. You want to get the rotation down to 30 seconds, much like doing 35mm in a small tank, agitating every 30".
You can do more of course, but you have to get your speed up to snuff. No safelight... that's the fun of it!
The PF slosher tray looks like a good method too, but for $70 you could make something with the same capability at a much lower cost.