Use a Protein Skimmer for Freshwater???????

It might sound like a stupid question, but hey, what the hell.......

The wife and I just 4 weeks ago started our first sal****er reef tank,
and I'm so impressed by the operation of the skimmer, that I wonder if
anyone has found a way to use a skimmer for a freshwater tank??

Of course, it is obvious that freshwater doesn't foam the way
sal****er does, just the same, I thought I'd pose the question.......

Anyone care to comment?

Thanks,

Greg