We've used the plastic dollar-store shoeboxes for many years, with rows of holes drilled across the lid with the smallest drill in the set (1/16 or 1/32, I forget which).
I keep an extra box to rotate the cats into. Paper towel liner on the bottom, insert fresh leaves, transfer cats from a messy box to the clean one. Toss away the messy box's paper towel, give it a clean towel and fresh leaves, and go on to the next messy box. At the end, the last box emptied gets cleaned up and becomes tomorrow's starter box. When the cats are little, they don't need to change boxes every day, but toward the end, those big guys are eating and excreting like mad! The best year we ever had at caterpillar-raising, we had 10 boxes with various sizes of caterpillars going at once. My son built a holding rack out of K'Nex to stack the boxes neatly and they didn't take up much room on the patio at all.
Certified Monarch Waystation #12
near Philadelphia, Pennsylvania