It is generally not recommended to dilute selenium toner with hypo clear. The toner lasts a very long time, the HCA not. so you'll be wasting good toner...

A few days ago I decided to intensify an irritatingly flat negative. I bleached in pot.ferri/bromide, then redeveloped in a pyro/carbonate mix. Worked like a dream, gave lots better highlight separatoin, and is reversible in case I don't like the result.