How is the ventilation in your coop? How many chickens in how much space? If the ventilation is good it shouldn’t smell inside the coop, the poop dries and doesn't attract much flies.I got fed up with the flooring of our coop and didn't like any bedding that was being suggested. Any amount of bedding in there for longer than a day became a fly magnet regardless of how often I cleaned. I wound up ripping out the wooden floor of the coop, filling in the entire bottom of the coop area with riverbed rock for drainage, laid hardware cloth over that to keep out potential rodents and whatnot, and then put vinyl flooring directly over all that and called it a day. With the pebbles underneath, the flooring is nice and soft so I don't need to worry about the birds making hard landings, and I just go in every morning with a dustbin and paint scraper to scoop up the nighttime droppings and transfer them to the compost- the birds don't use the coop during the day, so after the morning scrape there's nothing to attract flies until the next morning. I haven't had to wash the floor yet, but if it ever gets bad it'll be a cinch to toss some water in there and squeegee everything out. I keep one bag of shavings in the coop just in case it rains and the birds track in the damp. An extremely light dusting of shavings absorbs the wet so I'm able to easily sweep it out into the run and everything is dry again.
That's a very long way of saying, no, I haven't found bedding to be necessary inside the coop, and I actually far prefer my beddingless coop setup.
I have no floor and sand in the coop, a poop board under the roosts and lots of ventilation. After sunrise the chickens can go to the run, through an auto pop door. The chickens do not poop in sand of the coop area. They even like to dustbath in the sand.