Skittles in the Urge Jar

I’m thinking of trying a slight differentiation with the urge jar by using Skittles instead of beads.

I’d fill the jar up to 50 Skittles, and then for the next 50 urges I’d eat one Skittle instead of putting another one in, until the jar is empty, and then fill it up again.

Is it ineffective to tell the primal brain sometimes there’s no satisfaction and sometimes there is, so long as it’s always the pre-frontal cortex calling the shots? Or is this approach (no reward / reward) possibly going to make the job of the pre-frontal cortex harder?