This is a real Hack, but if you are savvy with JavaScript, you can probably write a few lines and enter them into your Address bar. This could even be bookmarked as "United Cookie Monster"

.
Instead of entering
http://united.com or whatever, you could try something like (all on 1 line):
javascript
: var now = new Date().toGMTString(); var names=document.cookie.split("="); for (var i=0;i<names.length;i++) {if ((i%2)==0){document.cookie=names[i]+"=;expires="+now+";"}}
That will execute the script as part of the current page (need to have united.bomb open). The handy thing is this could be automated as a bookmark on your toolbar.
I haven't tested it or anything, bit if you know what you're doing you should be able to come up with something that works... Maybe they should add a "clear cookies" link on .bomb. But I guess if .bomb were written properly, you wouldn't need to come up with hacks as a workaround!