Lime. I used it in my cow shed after removing my hens, before my rams had to go in - was a bit of a rush job, I would usually wash down with proper defra approved disinfectant as it's a concrete floor, but I was in a hurry (and it doesn't dry very quick in there) , so I spread lime everywhere, including up the walls. I used a lot, and made sure it covered everything (rub it around with a broom to get a good covering). Wear a dust-mask, and googles.