Wash plastic toys when they're new, and then on a regular basis, in the top rack of your dishwasher. To disinfect toys--especially after your baby's been sick or you've had kids visiting--wipe them with hydrogen peroxide. Stuffed toys collect dust mites, which can be a problem for a child who has allergies or asthma, so machine-wash them regularly. If the toy isn't machine-washable, surface-clean it with a mix of water and mild detergent. Air-dry it in a sunny spot indoors, then put it in a plastic bag in the freezer overnight.