Although I'm no authority, I've always felt that there was a difference between the two! Clean and Tacky, to me,leaves my hands stickier than Clean and Dull! So therefore there may actually be a difference in the formulation between the 2 and although they are designed to serve the same purpose( deep cleaning),Clean and Tacky might actually give the coverstock a slight tweak as far as tackiness! Just my thoughts!
Ken Reitz