wq! - I did the same thing with mine. I had small hairline swirls and general funk which is normal for a truck just off the lot. So, I washed the truck with dish soap to get all the funk off, then applied a nice polishing wax to remove any scratches or swirls, finishing with a pure wax alone. Once done, the thing looked incredible - almost glowed! I got a comment of "Wow, nice paint job!" from the attendant at the gas station afterwards...

I suspect that dish soap is "harsh" because it is meant to cut grease - heavy grease. Waxes are a sort of grease - and can be removed due to the chemicals in dish soap. I myself wouldn't use it after the occasional "strip down" wash and prefer a soap suited for washing cars. Whether or not it's hype, hey, for a couple of bucks - why not? There are no abrasives in dish soap though - unless you use something like SoftScrub (dear God, don't!)

My father's been washing his cars with dish soap forever, and has never applied wax more than once or twice. There's no oxidation present, nor are there any ill effects that I've seen... But on one car, there are hairline CRACKS in the paint on the roof (and roof only) so I'm not sure if it was in the paint, a certain circumstance, or what... It's on a Mercedes, which shouldn't have paint issues - so take it however you will.