I wrote a little bookmarklet that serves me pretty well for similar purposes:

    javascript:window.location=window.location.href.replace(/\?([^#]*)/,function(_,s){s=s.split('&').filter(function(v){return(!/^utm_/.test(v))}).join('&');return(s?'?'+s:'')});

It's much limited as it focuses on Google's links, but it works good enough for many cases.