Over the holidays I’ve build a little tool, Faff, to index and search the page contents of Firefox bookmarks. This allows searching using words that appear on the pages rather than in the bookmark title. It uses full-text-search with ranking / relevance and snippets, it’s quite WIP. More info at
It's written in Python command-line tool and uses SQLite's full-text search and Newspaper's text extraction, so a search over all my bookmarks takes only about 0.3 seconds although the indexing is certainly slow.