I'd strongly recommend and encourage all passengers to simply not remove their shoes at all, out of "medical necessity". Depending upon one's perspective, it may be more convenient to keep them on and have a TSO come over and swab them for you while you sit and wait.
I know that I'd rather sit and make one of them work for their pay than remove my shoes and walk in socks or walk barefoot across the floor. As a matter of fact, I intend to do just this when I fly out of IAD this summer for a vacation.