I've made a "L" shaped pvc feeder - been in use now for 6wks - it seems clean enough (chicks cannot poop into it, so it's just got a small amount of 'feed dust' along the back edge where it meets the wall). But I'll need to refill it soon. That would seem to be an optimal time to dis-mount it from the wall and totally wash it out. Yes? No? How long do you go between washes for a 50# bag of feed to go through? Thanks!