Reddit - Collapse [deleted] comments

// ==UserScript==
// @name           Reddit - Collapsed deleted comments
// @author         gavin19
// @description    Collapse deleted comments.
// @match          http://*.reddit.com/*/*/comments/*
// @include        http://*.reddit.com/*/*/comments/*
// @version        1.0
// ==/UserScript==

var collapseComments = {

    hideDeleted: function(x) {
        for (var i = 0, lenx = x.length; i < lenx; i++) {
            if (x[i]) {
                x[i].parentNode.setAttribute('style', 'display:none !important');
            }
        }
    },
    init: function() {
        var x;
        document.body.addEventListener('DOMNodeInserted', function(event) {
            if ((event.target.tagName == 'DIV') && (/comment/ig.test(event.target.getAttribute('class')))) {
                x = event.target.querySelectorAll('.content .grayed');
                collapseComments.hideDeleted(x);
            }
        }, false);
        x = document.querySelectorAll('.content .grayed');
        this.hideDeleted(x);
    }
}
if (document.body) setTimeout(function() {
    collapseComments.init();
}, 3000);
else window.addEventListener("load", function() {
    collapseComments.init();
}, false);