[whpalmer4]

I did a bit more digging, including installing Evernote to see how it accomplished the PDF to Evernote workflow. It installs an alias to the Evernote app in the Library/PDF Services folder, named PDF to Evernote. Apparently, the Evernote app knows that if it is invoked with the alternate name, it is to take the associated PDF file and add it to the database. Doesn't help us, unfortunately. Put in a folder alias as Dennis suggests as a "PDF inbox", then clip them one at a time from the Finder on a regular basis...

Sadly, it appears that sending an email with an attached PDF to user+omnifocus doesn't do the trick either.