Perhaps, though one might be able to cast a spell to plant the suggestion when he's not alone, what, whereas if one cast the Killing Curse under those circumstances it might be more difficult to successfully get away.

Another option might be to have the shopkeep contact him to bring him to the establishment. For example, if he were asked to come in to clear up a question of billing , what, or because an admirer has gifted him with a pair of boots and the cobbler requests a fitting.

If nothing else, the shops might provide additional insight. Proper research is so helpful, after all.

J