From what I have read people have varying success trying to get meds this way in foreign countries.
Metoclopramide doesn't really have any capacity to be used recreationally, so I sort of think that compared to other drugs they might be a little bit less hesitant to give it away.
However I also feel that a "legit pharmacy" is going to be "legit" whether you ask for opioids or prescription antibiotics. It probably depends on the pharmacy and pharmacist. I don't think I would wager a trip like that on it though.
From what I've read some users on this forum have been able to get prescription-strength antiemetics by lying about having nausea all the time or a sensitive gag reflex while brushing their teeth. I would probably try this route first.