The snippet could be written to run on the client or the server.

Javascript: I can't help you there I'm afraid. Are you saying you want to do this in the browser?

If what you want to do is rewrite a lot of HTML I think we'll be able to help.

Your best bet to post a new question with a representative (but fairly short) example of your 'junk' and an example of what you want it to look like.