I've sent a reply by email yesterday, but I'll post it here as well in case anyone else has the same issue.
Hello Tommy,
If you want a version that can process a 16 bit .WAV file, there's a
command line version of Stereo Tool (which includes the declipper) that
can do this. See
http://www.stereotool.com/ .
Alternatively, you can use Winamp + the DSP plugin to cleanup audio
(Winamp also has several disk writer plugins which write the result back
to disk), or any VST host (there are hundreds of those).