I realize this is an old thread, but I'm pretty good at this polishing stuff and just a couple of thoughts.
First, You keep the hangar clean by buying some of those cheap tarps at Harbor Freight. You keep your hands clean by wearing vinyl gloves, which you should be wearing anyway to keep the oils on your hands (and the scratches on your skin) from dinging up your polish job.
The bigger and more important subtext here is the search for the perfect polish job.
You get it once. Once. The first time you polish your plane.
Although you will get better at polishing, you will never be more impressed than the first time. It's like driving your first kid home from the hospital. You'll never drive that carefully again.
Once you start polishing, you're ALWAYS going to notice the imperfections in polishing. You simply have to get used to it because the people coming up to you drooling are not noticing those; they're back at seeing the "first time" thing.
Just as there's only one reason to BUILD an airplane (you want to BUILD an airplane), there's only one reason to POLISH an airplane: you want to polish an airplane.
I tell everyone who says, "boy, that's a lot of work," that "it's cheaper than therapy." They think I'm kidding; I'm not.
There's a loveliness about polishing that isn't for everyone. You're seeing every inch of your airframe. You get to know it intimately; you begin to be one with it. Like I said, it's not for everyone, particularly people who don't care if the chicks dig the polish or not. The fools. Chicks dig the polish, man.
BTW, I used the purple polish as part of a complete polishing diet. I like it. I would never use it on the whole plane. As good a job as it does, it will always look better out of the sunlight. So will your compounding job, but it will look better IN the sunlight than the purple polish.
I would NEVER use the purple polish without first using the "green juice" -- the oxidation remover. Don't ask me why; it just looks better.
It won't screw up future painting, assuming you're going to use a reputable paint shop that prepares the skin appropriately. The biggest threat to future painting, is future preparation.
One final tip: If you don't know whether to paint or polish after doing some polishing, you need to write a big check to the paint shop.
And if you want a polished airplane and don't want to polish, write me a big check instead.