Index existing posts

I'm installing Post Indexer on a site with pre-existing content. I understand that Post Indexer will only be indexing new posts that are published after it is installed, and can't re-index older posts out of the box.

My question is: Can I trigger it to index say the 20 most recent posts (from before it was installed) by manually editing these, setting them in Draft mode, and then re-publishing them. Will that trigger Post Indexer to add them to it's global posts tabe?