Back in the dim & distant past, you could get spearmint milkshakes here in Melb. Grew up on them. Then about mid 1980s the choice of flavours dropped back to to vanilla, choc & raspberry - caramel if you were lucky. This was about the time that Big M started putting their wares in supermarkets, and you could no longer get milkshakes in milk bars as a matter of course. Some holdouts of course but in general the spearmint milkshake died right then and there. Could be time for a revival.