A couple times I have seen an experienced dancer use this when there was no one else nearby. The "who me?" was not really a question, but rather a coy flirtation.
In general I advise against using "who me?", but this might be an exception. I have no objection to people flirting from afar, but a smile and nod is still needed to seal the deal.
Please feel free to share your experiences and insights on this topic.