Polly-O Six Flags Discount Tickets for Recycling! - POLLY-O and TerraCycle, Inc. have partnered with Six Flags for a summer recycling drive at Six Flags parks across the United States. Visitors are encouraged to participate by bringing their specially marked POLLY-O String Cheese and Twists packaging to the park entrance to receive a discount, Baltimore/DC Six Flags America, 5/15 through 8/31 www.sixflags.com.