Guys, we get that you're on the road and you gotta piss. This is just unacceptable. Even a minor amount of piss splash is going to ruin the order for most sane customers.
What is the correct procedure here?
In a discrimination-free restaurant like McDonalds, anyone can use the restroom. Go take care of business before you go take care of business and make sure you wash your hands. If it isn't that kind of place, go a head and ask the staff and most of the time they will let you.
Once you are ready and with clean hands you can proceed with the order! Should be common sense, folks.