Removing Bookmarks for courses (issues with purchasing through bookmarks on retiring materials)

We wanted to find out if there is a way on the course level to restrict bookmarking a course or be able to remove all bookmarks for users?

This has come up as we periodically retire courses. The process for us is to remove the course from the catalog, remove from search, and to set the expiration date to the final day of enrollment for the final user. We do this to keep using from further purchasing but have found if users have bookmarked the course they can go and purchase technically retired content. We have added retired to the course name, but get ignored by users.