2001 Tahoe cassette tape cleaning

''Cln'' flashes when a cassette tape is inserted in the 2001 Chevrolet Tahoe with AM-FM Sterio with CD player and Remote Cassette tape Player. The mannual says the tape heads need to be cleaned. The cleaning tape ejects because the cut tape detiection feature is active. The manual says to press and hold AUX for 5 seconds to deactivate it - does not work. The manual says to press and hold eject to reset the tape cleaning timer - does not work. Please advise what will work?