I need to tone some 200 prints to make them archival. They are on Rc papers and I have a bottle of KRST handy to mix. I'm concerned about the fact that Rc papers can be ruined because of a too long immersion in chemicals or in water. If the "accepted" standard is to tone to 6 min @ KRST 1+9, counting all steps of development, stop, fixing, toning, washing the total of 15 minutes can be exceeded thus letting water or chemicals penetrate in the paper base, peeling off the emulsion and ruining the print. What are your method of toning Rc prints without ruining them?