LaTeX.org

You can use this tiny little awk script
#!/usr/bin/awk -f
!/^[ \t]*note/
If you save it as, e.g., "cleanbib" and then run "chmod +x cleanbib" so that you can execute it, then you can run a command like this:
$ cleanbib bib_with_notes_field.bib > bib_without_notes_field.bib
It works as long as ...