Ok Ian, follow this.
Process #1, Dev, Stop, Fix, wash (8L wash) Process #2, Dev, Stop, Fix, wash, HCA, (4L wash). In process #2, the total effluent is 2x more concentrated due to the decrease in wash water. It saves water but increases BOD/COD by 2x and increases other pollutants by the same amount. And, at say 5 g/L HQ in a developer, I would hate to say my urine contains that much. I'm a dead man. Even diluted with 8L of water, that is quite a bit of HQ!
Now in process 2 we must also add in the HCA and this increases total salts by the molar amount of sulfite present.
This is not to say that the amount of water used is not reduced. I am pointing out to you that by doing so, you increase the burden on sewage treatment and actually increase the load of chemistry used.
In addition, depending on how you dispose of your chemistry, the disposal process must take into account the HCA and the Hypo and Silver salts in the HCA.
Did you ever calculate the amount of HQ in discarded developer, the amount of salts in a process +/- HCA and etc? If you did, you would understand what I am saying. This, IMHO, is not patronization, it is pointing out simple facts.
BTW, think about the normal levels of HQ, Pyrocatchin, Sulfides, or Thiourea in Urine vs that in a developer or toner. You are comparing micrograms in one case vs grams or milligrams in the effluent in another.
PE