I have written some code that takes a string of html and cleans away any ugly HTML from it using jQuery (see an early prototype in this SO question). It works pretty well, but I
How about removing the scripts first?
var wrapper = $('').append($(html).not('script'));
Assuming script elements in the html are not nested in other elements:
var wrapper = document.createElement('div');
wrapper.innerHTML = html;
$(wrapper).children().remove('script');
var wrapper = document.createElement('div');
wrapper.innerHTML = html;
$(wrapper).find('script').remove();
This works for the case where html is just text and where html has text outside any elements.