I assume you have a darkroom. Otherwise, this is going to be very difficult.
To answer your actual question, lifting the bundle of tubes out and replacing them back in about 3 times every 30 seconds would be consistent with my agitation in tanks. I'd suggest running some tests, especially since you have so much film to process.
Have you considered tanks and hangers? With 1 gallon tanks and 4x5 film you can easily develop 24 sheets at a time.