The way Utd do it, is you don't know if you will be selected to pick up on match day when you purchase.
Then if you're selected to pick up on day and someone else tries to collect your ticket, or you fail to turn up, or if you try to cancel the order - then you get a ban for 12 games & if occurs again can lose season ticket.
So it would be effective in stopping people applying for away tickets they don't intend using.
I'm not advocating this policy, just pointing out that it would work if the objective was to ensure correct person used each away ticket. Once bans started being handed out people would amend their behaviour.
My own view, as has been pointed out already, is that we don't sell out our aways or have anywhere near as many want it go as Utd, Liverpool do. So it's not needed yet. But I think as/when we do start selling out all the time then it's the easiest and most effective policy. Perhaps with a rolling points system.