No one is quite sure who first discovered the cleaning method, but its effectiveness is indisputable: If one person uses a brush to swirl soapy water in the tray-cleaning bucket while another person plunges a dirty tray into the water, the tray will come out clean. The method is affectionately called “the swirly.” “The only days we can’t do it are nacho day and pasta day,” said Alexander Cohen, a fifth-grade Eco-Volunteer. Cleaning recyclable polystyrene trays at lunchtime is just one of the steps students, parent volunteers and staff at Bridge School have taken to promote recycling. What began as a parent-led initiative in which lunchtime recycling was done only on Fridays has evolved into a daily school-wide effort, with 90 student volunteers giving up recess time to help on a rotating basis.