I don't know if Whites are different eaters than Greens, but my Red Eyes (they are not quite adults) get fed now every other day (was every day) and I put in anywhere from 6-10 crickets each time. Now these are not adult crickets, they are usually around 1/4".
I do lose a couple now and then to the water area but they do eat the rest, as I never see any big crickets. The crickets can hide since the tank is so dense and there are places they can go that the frogs can't. My frogs are always waiting for their feedings so I don't know if mine just eat alot because they are still young or what. They are not fat and are actually quite slender, so maybe there is just a difference between Whites and Greens and Red Eyes.
So without knowing how old the frogs are, I would probably err on the greater side and if there were leftover crickets, cut back. Also if they are adult frogs they could go every couple days.