Which script are you using? I'm not aware of any by Rob that do OO->OPML except as a step between OF and OPML. Not sure why he would write one, given that OO has built-in OPML export...
As a quick and dirty hack, the following bit of Applescript will remove all the notes from the front document:
Code:
tell application "OmniOutliner Professional"
tell front document
repeat with myRow in rows
set note of myRow to missing value
end repeat
end tell
end tell
Be sure you run it on a duplicate copy!
(If you've got the non-Pro ("OmniOutliner Amateur"? :-)) version, just remove " Professional" from the "tell application" line)
As another idea, on the
OmniOutliner Extras page, there's an export plug-in that goes to Markdown, if you've got the Pro version.