I don't like being tied to the tank; every 2 or 3 minutes
a few inversions. I've time between for mixing a fresh
fix, rinsing bottles, mopping up, etc. Same with the
fix, twixt agitations I prepare the Photo-Flo. Dan
When Ralph said "rotation," I thought he meant continuous horizontal rotation on a roller base.
As for the twisty rod, it worked fine for me. That was the only way I agitated my Paterson tanks until reading the agitation debates here. I still use it for the first 30 seconds with each solution -- back and forth, like a washing machine -- then inversion at 30 second intervals.
Has anyone even ever figured out if it even matters if it's done every 30 seconds or every 60 seconds? If anything, you could do a trail-and-error test to figure out which one you like best...
I teach an intro B&W film course, believe me modern films will give good (although perhaps not actually their best) results with a wide range of variations on agitation (and other variables) during processing. I noticed a student doing the cocktail shaker thing last week, even though that roll of FP4 got a LOT of agitation it was perefctly printable. Having said that once you progress beyond beginner consistency is IMO more important than exactly which method you use. You want to ensure that the only variable you change is time so that the effects of time changes are predictable.