According to forums, the effect of the Potage is to erase an ability from your chocobo. Unfortunately it is not mentioned how that works, so be aware if your bird has two abilities, that it might erase any of them.
It seems a total of seven lethe potage can be traded to a starving chocobo. We traded a total of six to bring the chocobo to "quite full." The first three were traded one at a time.
The first three single trades did not result in any apparent changes.
Three were traded all at once on the fourth trade. While there was no apparent animation or message regarding the ability, it was no longer listed among the chocobo's statistics.
Used one lethe pottage to strip Gallop off a newborn chick. Worked 1st try.
Potage (from Old French pottage; "potted dish") is a category of thick soups, stews, or porridges, in some of which meat and vegetables are boiled together with water until they form into a thick mush. Potage has its origins in the medieval cuisine of Northern France and increased in popularity from High Middle Ages onward. A course in a medieval feast often began with one or two potages, which would be followed by roasted meats. During the Tudor period, a good many English peasants' diets consisted almost solely of potage. Some Tudor-era people ate self-cultivated vegetables like cabbages and carrots and a few were able to supplement this from fruit gardens with fruit trees nearby.
Some potages that were typical of Medieval cuisine were frumenty, jelly (flesh or fish in aspic), mawmenny (a thickened stew of capon or similar fowl), and pears in syrup. There were also many kinds of potages made of thickened liquids (such as milk and almond milk) with mashed flowers, or mashed or strained fruit.