What have you been using on your coop floor for the last 2 years?
Are you talking about the actual coop, or the run?
I don't think any chicken floor would actually be sanitary, but some litter methods are easier to maintain than others, and everyone has their own preference. I like to use pine shavings on the floor
and a poop tray under the roosts to catch most of the droppings. I fill that with Sweet PDZ and just scoop daily like cat litter.
Lots of people use sand in the coop, which is fine if there's no chance of it getting wet, but you will have to sift the poop out a lot more often than with shavings, because it won't decompose. I only change my shavings once a year... the coop litter goes in the run, and the old run litter goes in the compost bin.