Goal and options: rolling pin
output answer: can flatten paper

Goal and options: ball
output answer: rolls on ground naturally

Goal and options: How can I clean my tub with a homemade cleaner?
output answer:
Make a bathtub cleaner paste of one part hydrogen peroxide to two parts baking soda (or cream of tartar). Rub the paste on the stain and let stand for 30 minutes to one hour, then wipe and rinse. If necessary, repeat until the stain is gone.