People manage their litter and clean their coops in different ways. There's no one right way to do it.
I prefer using deep litter in coops and I don't disinfect my coop. For a deep litter coop, I clean the litter out once a year, in the spring. I like to leave a little litter in the coop, to reseed the composting organisms faster. I wouldn't be trying to kill all the good organisms off in the coop. For me, it would be like hosing down my compost pile with bleach, which would be counter productive.
If I ever had a disease outbreak in my flock and my coop was contaminated, I would do a complete clear out and disinfect. That's just never happened to me. I don't bring in adult chickens and I'm careful where I get my chicks from. I try to house and feed my chickens in a way that keeps them healthy, plus their immune systems strong, too. I think I've also been lucky, but I actively work at not having disease problems.
Some people like to clean out their coop more often, instead of using deep litter. Lots of people just clear it out, then wash down the walls and floor. Other people do that and then disinfect. The disinfecting gets done before you add fresh litter back into the coop. Some people like to spot clean in coops between clear outs. Some people like to have poop boards or bins under the roost that they clean every day or two.
Chickens just want to live in a coop that isn't overly wet and smelling like ammonia. Any way you can manage their litter that ends with that result is great with them.