I've just done exactly the same, tall box. Two rows with bamboo sticks. I have two PC fans blowing on each row from one end.I dried my plants in a cardboard box this year. Hung them on wooden bamboo sticks. Don't open the box too much at first, let the moisture and humidity stay in the box to slow dry. Don't make too many holes.
Then start opening the box up.
The fans usually run on 12v but the usb supply is putting 5v shared between the two so they are running super slow. I reckon I should be ok as it just keeps the air moving round in the box and letting it naturally vent out the loosely closed top.
Currently at 67% and 22c after just setting up. Hoping this drops... If not any advice?