Eric found another way for his son to play with a magnetic stroller toy:
My six-month-old son has a plush rattle that has a magnetic clasp wrapped in fabric that can easily attach to his car seat or stroller. The other night, we were in an auditorium listening to my daughter's recital. To keep him occupied, I attached the rattle to his little wrist, as a handcuff of sorts. He could swing it around, grasp it with both hands, and even if he "dropped" it, it was still within easy reach of his hand. If I needed to take it off, a gentle tug would unclasp it.