Or how about "modeled after Batman"?
Goku is Goku. Clark is Clark. Don't try to make one into the other.
I think I'd rather not see it done at all, but if it must be part of the mythos, then do it very, very rarely (once a decade is more than enough I think), and don't let just any writer do it.
The first time I saw sundipping back in OW@W I thought it was pretty damn cool and a great finale to the most cosmic Super story I had read at the time. But it's totally a matter of diminishing returns, and is less cool with each subsequent use.
I'd think there should be some kind of major drawback involved, to help prevent writers from abusing it. Maybe take a page from All-Star and say that sundipping runs the risk of Clark getting space cancer, or something.