The first wash tray or washer needs to be emptied and refilled if it is to be used for the second wash.
The intermediate wash-aid step should be done in a separate tray with agitation using fresh solution.
The final wash needs fresh, running water.
Temperatures need to be close to 20°C
Times from Ilford are predicated on using very fresh fix and short fixing times. Exceeding either of these parameters will increase wash time.
If you are using a one-bath fixing regime, then your throughput capacity will be rather low: 10 8x10s per liter for "optimum permanence," or 40 8x10s per liter for "commercial" standards. This latter may be too generous.
If you exceed the 60-second fixing time with drain time or whatever, you'll need to wash longer.
If you tone, you'll need a much longer wash; Ilford says 30 minutes for the final wash after selenium toning.
If you keep getting stain with your RHT, and are using fresh reagent, doing the test in subdued light and reading the result after only two minutes, then you simply need to extend your wash times.
Personally, I use the old-fashioned Kodak sequence, but with a longer wash-aid step. I fix in less-concentrated rapid fixer using a two-bath fixing regime for 2-2.5 minutes per bath, then give an initial five to 10 minute wash (often longer, in a holding tray), then a 10-minute treatment in wash aid, and then a final wash for 30-60 minutes. Never a staining problem.
I don't like the short fixing times with the Ilford sequence, Keeping wet time in the fix to just 60 seconds with a two-bath regime and large prints is just not practical.
Best,
Doremus