I originally read about it here on Advrider, but I can't remember where exactly. I was skeptical too, and maybe I'm not the best person to sing its praises yet since I haven't even ridden my bike yet
, but I sure am sold. I tried it because I was inches away from painting or otherwise coating the engine. Although I didn't want to go that route, I also knew I didn't want to fight aluminum oxide on a continual basis. This is the perfect solution for me.
I've had solvents, grease, and all other means of chemicals on the finish, and just like a good wax (that's really all it is - wax with coloring pigments in it), it helps repel everything. Just like wax, I suspect it will indeed wash/erode away over time and need to be reapplied, but not after one or two rainfalls.
A tube is under $5 and will damn near cover your entire bike twice - what do you have to lose?
EDIT - And, no, I am not in any way affiliated with Rub N Buff!