U.S. Pat. No. 4,511,478 to Nowinski et al. describes several types of oxidation-reduction initiators, including: (1) peroxides in combination with a reducing agent, e.g., hydrogen peroxide with ferrous ion or other transition metal ions, or benzoyl peroxide with an N,N-dialkylaniline or toluidine, and (2) persulfates in combination with a reducing agent, such as sodium metabisulfite or sodium thio