The problem with mixing selenium toner with a wash aid, which is primarily a sodium sulfite solution, is that the sulfite will oxidize long before the capacity of the toner is reached. This does not mean that you can't keep using the toner, however. And, since Ilford advocates using a wash aid after toning, I don't see what the point is of using more sulfite in the toning bath, unless, of course, the toning bath is incompletely formulated to begin with and needs more sulfite (which I doubt). I imagine that this recommendation is a hold-over from earlier times when this was more common practice, and has simply not been reviewed for a long time. (It also sells more wash-aid, and toner too, if you are tossing toner after the capacity of the wash aid has been reached...).
Originally Posted by silveror0
In any case, my use of KRST without any wash aid mixed in has proved to work just fine.
As for transferring directly from fixer to toner: As long as the fixer is not too acidic, then there is no problem as long as the prints have been adequately fixed. Inadequate fixing (read not-completely fixed silver compounds remaining in the print) and/or a too acid fixer will cause staining in the toning bath. I use Ilford Hypam or Rapid Fix at 1+9 for my second fixing bath and have had no problems transferring directly from fix to toner. Maybe the 1+4 dilution would be to acidic; I've not tried that. Plain hypo+sulfite or any of the alkaline fixers work fine for this as well.
I imagine that if you wash between fix and toner then you need to wash completely before toning. Then, of course, you need to wash again after toning. I find it easier to use a fixer from which I can transfer prints directly to the toner.