pon suggests a wrongly learned product — how do I get rid of it?

Open product search (the search bar or „+“ in an open list) and switch to „Recent“ if needed; there, swipe the product left.

A product you created yourself is really deleted; a product from the catalog is only reset to its default values (your learned prices, locations and attributes for it are dropped). A brief note („Deleted“ or „Reset“) confirms it.