No idea is silly or dumb. Remember that people laughed at ear muffs and Fulton's folly which are big successes today. Pet rocks and Slime are jokes that made their inventors millionaires. Build on ideas. Piggybacking is part of the game.
S stands for substitute.
Cardboard or paper board in egg cartons replaces the plastic foam cartons. Paper wraps are being used by MacDonald's instead of the styrofoam cartons. Play Doh replaced clay. Paper clips, staples, pins, clamps can all be used to clip paper together. They will suggest pens, fountain pens, ball point pens, chalk, colored pencils, markers, paint, plaster, clay, soft bricks, etc.