It's been a little over a month since I applied Protect All to my tt. I thought I would give an updated report for those who are interested.
This past month I've only towed the tt about 300 miles and most of the time it's been kept under cover. Temps have been in the 100's for the past few weeks and we haven't had any rain, so very dusty.
Under those conditions the tt wasn't really dirty except for the layer of dust the wind has stirred up. I went out to wash it this evening. When spraying it down the water ran off like "water on a ducks back!" Taking the dirt with it! I really didn't need to use soap, but had it fixed up so I did anyway.
So after 1 month the Protect All is still doing it's job very well.