Cleaning up HTML from textarea

I have a page with two textareas, where registered users can fill them with HTML codes. First one has TinyMCE (so HTML is cleaned up), but the other one does not, since I expect the code to be inserted as embed codes from other sites (mostly sites that provide maps, e.g. Google Maps, MapMyRace.com, etc). But problem is that those other sites may provide different tags, not just `` or `