Once you have the denture cleaner, grab your offending plasticware and send those tabs to work. Simply fill each container with warm water. Now drop in two or three denture cleaning tabs, depending on the amount of staining. The tabs will begin right away to dissolve the stains. Let the plasticware sit overnight with this solution inside. In the morning, rinse and wash out your plasticware by hand. It should look as good as new!