no never. had mine 5 years now and have never done it. Can't see anytime when I would as it would just take forever to dry especially as mine (like many) is a double floor may not ever dry out and just rot
Edited to add what I did do was drill some rows of holes so if the horse weed in there it could drain out properly
Had mine two years now and never hosed. It has rubber mats & I put a couple of buckets of Aubiouse on this & makes it easier to clean after use & it absorbs any wee!
No, I keep it full with LOADS of shavings to absorb everything, then take out all the wet after every trip. Have had our box 12 years and only now starting to show a little rot in the corners.