This question received a major edit after a couple of answers, the edit was done by the original asker in order to remove the, shall we say, "ethically dubious" elements of the question, presumably because of the backlash they were receiving for these aspects.
This edit substantially changes the question and in the process invalidated my answer. Had the edit been done by another user I'd have simply rolled the edit back, in this case however since the edit was done by the OP I'm unsure of how best to proceed. Should I remove my answer?
EDIT: Well, predictably I received two DVs in quick succession after the "new" version of the question had been live for a while. Presumably from people who read the edited question and my answer and decided I was clearly some kind of anti-assist-dog or anti-disabled-person jerk. Of which I am neither so I've removed my answer for now. Still interested in answers to this meta-question though since in more general terms than just the linked question it'd be good to know what the best practice is.