I just got my FEC120 2 weeks ago and clean it every other cook. Usually a long cook and a short cook less then 14 hours. My observation is there is 40 or 50 pellets on the floor of the fire pot chamber and maybe about 4-5 oz of ash in the pot. I think the ash in the pot is the biggest concern. You really want that pot empty when you start the smoker. Less ash blowing around # 1 and a good even start.
I bet if you cleaned it out every 2 days you would be fine.