Iac, I question that talmid’s memory. The OU Kosher website says “Rav Belsky ruled that one may even place hot food directly on top of a paper towel on Pesach. The starch that is used in paper products in America can be assumed to be at most only kitniyot, and because the starch binds strongly to the paper, it is unlikely that any starch will transfer into the food. Poskim write that one is permitted to hang lamps of oil above their table, even if the oil is kitniyot and may drip into the food. Unlike chametz, which cannot become nullified on Pesach in any proportion, kitniyot will be nullified in a simple majority.”
so far as I know no one holds that kitniyot are safek chametz. This is evident from the fact that an Ashkenazi may not only keep it but even cook for a Sepahardi (or even for himself if he is Israeli and Isru Chag falls on Shabbat.
