Every person has strengths and weaknesses. When you hire someone you are hiring not just the person, and not just the strengths, but the weaknesses too. You cannot hire half a person. In other words, no one is perfect.
Surely you can expect someone to work on his flaws, yet a phegmatic person will always find time to kick off his shoes and put his feet up, and the thinker's mind will drift. A sanguine will always be late, and a choleric will always be annoyingly bossy and a melancholy annoyingly solemn and organized.
Those with creative minds will tend to have a messy desk, and that's not so bad because it's because they have cluttered minds. If you want the ideas and the hard work, you'll have to put up with the occasional mess. That's just the way it is.
So don't call the RT at home to tell him to come in and clean up his mess by the ABG machine. If you can't stand the occasional mess you're either gonna have to fire him or get off your lazy ass and just clean up the mess.
Of course if you fire him you're going to have to find someone else to do all the things you love that he does. As the old saying goes: You never know a person's true value until he's gone. So if you have a good worker, put up with all of him. In other words: put up or shut up.
You can eat half an apple, and you can eat half an orange, but you can't hire half an RT. It's common sense.