Wash the toy. Use soap or dishwashing liquid to clean the toy completely. By washing away the dirt and grime, you can better evaluate the level of rust. In some cases, a good cleaning is all that is needed to remove surface rust.
Scrub the rust stains. Use steel wool or a scrubbing pad to remove the rust from the toy. Apply mineral oil to the stains that don't respond to the scrubbing. Use a paper towel to apply the oil. Leave on for 10 to 20 minutes. Scrub the rust stains again. Wipe clean. Repeat the process if rust is still on the toy.
Make a paste of salt and lime juice. Pour a little salt on the rust stains, then pour lime juice or squeeze a lime over the salted areas to make a paste, suggests the Earth Easy website in the article "Non Toxic Home Cleaning." Let the mixture remain on the toy for two to three hours. Scrub off the salt and lime juice mixture. Wipe clean. If rust still remains, repeat the procedure.