[Dave Miller]

It makes sense to allow a standing period between fills to allow more time for the contaminants to leach out of the emulsion, however many have used the Ilford method for many years without problems. Your description is slightly at variance with Ilfords by the way. Ilford say, and I quote: "After fixing, fill the spiral tank with water at the same temperature, +/– 5ºC (9ºF), as the processing solutions and invert it five times. Drain the water away and refill. Invert the tank ten times. Once more drain the water away and refill.
Finally, invert the tank twenty times and drain the water away." Not so many refill/dumps as your describe.