The first time I stepped in to a restroom facility for one of the Corps sites we are constructing in Afghanistan I pointed and said, "What's that?" A low, tiled seat face some very low sinks. It looks like some old stadium urinals except for the seats in front of it. It is an ablution area where the Afghans go to wash their feet. The only reason I can tell you how many restrooms we've turned over that were trashed within 2 weeks is because it's a subjective number rather than an objective number--all of them. The foot washing is a mess, even in the areas that aren't set up for it. And the most of the mess comes from the ablution process.
When I first got to Afghanistan I was in civilian clothes and the moon dust got all over my shoes. When I finally changed into my uniform, I washed my shoes thinking they were done getting dusty. Two days later I washed them again but didn't clean them again until I got to London in August. I'm slow, but trainable.
This time I came home was the same. There was a chance in Kuwait, but it does little good to wash Afghanistan off your shoes only to have it replaced immediately by Kuwaiti dust. So, in an incredibly symbolic manner, I entered the restroom in Frankfurt Airport and washed Afghanistan off my shoes.
I'm still unclear of whether there is a religious symbolism in ablution. I know it isn't absolution, that comes on Fridays when they go to church. But there is a cleansing feel to it.
I did clean up the mess I made. Ablution will really mess a bathroom up. Also picked out the boogers, moon dust makes bad boogers.