Considering she's a gray, with white hind hooves, and the urine splashes all over her legs... Oh, it's horrible from where I'm cleaning it
I have mats and the mare somehow tracks in a bucketful of dirt, so I have a muddy-urine mess... Hose it out and then I always get a few puddles left after sweeping. Her frogs also soften from standing in it, shamelessly of course. Wouldn't you know, I spend time with her at least three times a day, and I am allergic to horses? The urine makes me sneeze and wheeze, cleaning pine chips frequently isn't an issue, but the urine sitting there on the mats... Bleh! I take allergy shots for this... and my mountain of indoor/outdoor allergies.
Muppetgirl--- GENIUS, I never thought of putting the chips outside! That might work
Locking her out to the paddock concerns me a bit, because she tends to roll more, and rub her mane on the fence. She gets ungodly dirty. Looks like a powdered doughnut, only dark gray to the color of the sandy dirt. Oh well, though, if it helps her pee outside.
My neighbor has her horses trained to pee in buckets. I tried with my mare, but somehow got her to defecate when she sees me with the stall rake/fork... Hooray.