Mine is plywood, with a chicken wire lid where the heat lamps sit on top as necessary. When it gets dirty, the chicks are temporarily put in a box, and the shavings are removed. I have a stick on lynolium bottom to prevent it from rotting. The new shavings layer does not cause a problem for slips as they walk on the shavings.
I used a very weak bleach solution on our coop about twice a year when we do our major cleanout. I keep the hens away until it is well washed and dried out so they dont try and drink the water. I have not raised chicks yet though but I would think a similar solution would work to clean a brooder out if there are no chicks present yet.