my Chickens Hang Out On My Poarch Too. They Even Perch On The Back Of The Poarch Swing. Sometimes I Dont Like It Cause I Know What Is Going To Have To Happen And It Involves Me Cleaning Up The Poop. But I Think Ok They Just Want To Be With Us. So Most Of The Time Its Not A Big Deal.
You could set up one of these motion activated sprinklers for a while to teach them to stay off the porch. Of course, it will spray you, too, but maybe you could use a different door for a while while they're getting the idea?
We already have a motion sprinkler from when we lived near a feral cat population but we just know we'd forget and get sprayed ;-)
I've started rushing out and throwing water at them. Seems to help a bit. It's not really too bad overall. We have and mudroom, and wood and tile floors, so a random tracked-in poo isn't that big of a deal.