I would default to the instructions going with the brand you use as they vary. In general though I'd dust crickets every meal with calcium 5x per week and dust them with the multivitamin the other two.
Ca dust on crickets only 4 days of week , then Ca + Vitamin powder mixed on them 3 - 4 days.
About enough dust in each case to cover a thumb nail , I use a small round take away sauce tub with a lid. In goes the dust, followed by the crickets , gentle shake , hey presto ! dusty crickets .
I got a tall plastic vase from the dollar store to dust crickets in. They can't climb or jump out and it makes it easier to pour the crickets in his enclosure. I dust multivitamin in morning and calcium at night NEVER mix them as the calcium can negate some vitamins. It says so on the label. I also use the same vitamins as the op. He only gets calcium on the weekends