I have heard it works but it is expensive like you said. I have not used it myself.
The biggest problem I think with the stock headlight is that they leak, the condensation gathers on the inside if the lenses and over time they look like they do.
Baking the headlights to separate the lens from the housing seems to be the best solution without destroying the lights in the process.
I just bought different lights but some people have had theirs turn out like new after baking them and cleaning them really well, some even wet sand the lenses.
I guess the real trick is to get them to seal so they do not gather condensation on the inside again.
That's about all I know about it.