theres for and against cleaning and not cleaning as been said before its getting the right ballance and what suits you , damp or wet droppings arent any good for the birds , dropping omit amonnia so it needs to dry out pretty fast amonnia plus hot loft can cause gases to build up in the loft which will impair the birds ability to perform toxin levels raise in pigeons and reduces there performance , i have used both extremes and have returned to scrapping twice a day , the reason fotr this is you can see the droppings and maintain the health of your birds harder to do in deep litter imo , plus dont have contaminated feed or water from faeces still damp and no gases building up in your loft reducing your birds performances