Thanks for the tip! Unfortunately this trick is finicky and doesn't work for all websites, at least right off the bat.
I've been playing around with it and here's what I came up with:
1. The URL that's saved in 1Password makes a big difference. If the bookmark doesn't work, then try editing the URL that's saved in 1Password. ie. use http://www.website.com
instead of http://www.website.com/welcome3.html
. The "Go & Fill" option seems to be more flexible with the URLs.
2. Launchbar can read bookmark files in html format. Drag the files that you want to into Safari and then export those bookmarks. Edit the file in TextEditor to remove the URLs you don't want to include and then in Launchbar add a new "Web Bookmarks" -> "Custom HTML Bookmarks file..." and select the bookmarks file that you just exported.
I used a custom bookmark because I don't want Launchbar to index *all* of my bookmarks. Launchbar should have the ability to add individual URLs manually. I'll suggest that separately.