How do you open a plastic piggy bank without a plug? Just grab a butter knife, slide it into the coin slot, and tilt the piggy bank upside down. The blade of the knife will act like an emergency escape slide for the poor coins imprisoned inside. Is piggy bank good for kids? To further enhance their education, parents can also pay some amount of interest on the amount in their piggy bank and see the joy on their face. Here's why gifting a piggybank to your child is a good idea: A piggybank encourages savings as it provides children with a physical place to store the money in. Why do kids love piggy banks? An easy means for children to learn how to save money is with a piggy bank. It is an effective way for parents to teach kids the value of saving rather than spending money. Plastic piggy bank toys are excellent reminders for young adults and parents who may forget the importance of saving.