The present invention provides methods for producing exfoliated clay platelets from a swellable clay material. In embodiments, the method for producing exfoliated clay platelets includes providing an exfoliating agent comprising an anionic extractant, and exposing the swellable clay material to the exfoliating agent, wherein the exfoliating agent produces exfoliated clay platelets from the swellable clay material. Methods for treating paper precursors and paper sheets are also disclosed, as are paper products formed from such paper precursors or paper sheets.