I am not fond of mayonnaise. (Then there’s McGehee, who is really not fond of mayonnaise.) Still, your go-to person for mayo hatred is Amelia:
When is it appropriate to use mayonnaise?
Never. Well, never as condiment, anyways. Mayonnaise is acceptable if you’ve ingested poison and need to induce vomiting, but only if other means are not available and time is truly of the essence.
Amusingly, this is the top of the Wikipedia page for “Vomiting”:
“Vomit” redirects here. For other uses, see Vomit (disambiguation).
“Emesis” redirects here. For the butterfly genus, see Emesis (genus).
“Heaving” redirects here. For the up-and-down motion, see Heave.
“Puke” redirects here. For other uses, see Puke (disambiguation).
When the aliens come, as they must, I’ll remind them that this world of ours is so incredibly diverse that there’s a disambiguation page for “Puke.”
(Typed while eating a ham sandwich. No mayo.)