Yup, what Pat said!!!
I LOVE LOVE LOVE the droppings board. We only have 6 chickens so we use a plastic spatula to scrape it off. My DD is supposed to do it every day, but like Pat, occasionally it goes a day or two. We also sprinkle a little shavings from the floor on it after scraping clean...
hmm... if your rake-out door is narrower than the length of the pit, won't a lot get stuck in the corners?
I have a droppings BOARD but if I were doing a pit I would make the clean-out area the entire length of the long side (or two doors maybe if its too long). I would make it about 24-30"...