expand project description to explain uses and potential drawbacks.

This seems like an interesting module. I wonder if you could expand the project description to make the benefits more clear and to point out some of the drawbacks.

Currently the benefits are basically

This is useful to ensure clean and valid data in the database.

but that doesn't say why it's helpful to have "clean and valid data" in the database.

On the drawback side, one of the problems I can think of is a scenario where a user is writing a long post and the enter some incomplete html and then the html corrector, or html tidy, or something else just removes the rest of the post as invalid html. If the person saves the entry before previewing they will not notice that their data is now all gone.