There are a few factors to consider. Number one is ventilation. A well-ventilated coop almost never smells, so the first thing I would look at is adding some ventilation to your coop, because 10x5 should be plenty big for 5 birds.
What kind of smell is it? If it is a musty, moldy smell, is the straw getting wet? That can be hazardous to their health and in that case it should be removed. Or is it an ammonia smell? That is from their poop and should be alleviated by the added ventilation.
If the smell is caused by dampness, you might look at where the moisture is coming from and if you can prevent it. Or, you might find that sand is a better option for you because it drains better.
It is your choice how you want to handle the poop/bedding/cleaning. Some people prefer to do what is called "deep litter" where, instead of cleaning it out weekly, you start with 2-3" of bedding and after it has been pooped on, add more bedding on top, and so on. After 6 months or so, you end up with a deep bedding layer that can be scooped out and composted (it may have already started to compost in place). I do DLM and only empty my coop out twice a year. To keep it fresh, every few days I throw a handful of scratch into the coop. The chickens turn over the bedding looking for the scratch, so you can hardly see any poop - and the coop smells of fresh straw most of the time.
