The breeder where I got my pullets would put fresh feed in for two days, then on the third day would leave them to clean up all the food off the floor. The floor was always dry, so he knew the stuff on the floor was dry and no more than three days old.
One of my girls in particular (a Light Sussex) just stands there spinning the hanging feeder with her beak, flinging food all over the floor.
She seems to think this is great entertainment.
My main problem is wild birds eating the chicken food. Eventually I will invest in a treadle feeder but for now I have to settle for feeding all the neighbourhood birds as well as my own.