Use efferdent or someother “false teeth” cleaner. Put hot water into the item you want to clean and then drop an efferdent tablet into the water. Let it dissolve and sit for awhile. Spill out and rinse with clear water. This is also great for vases. Syber
Bleach will certainly work and it will be safe to drink out of later. Just dilute the bleach – -3 parts water to bleach and allow to sit overnight. You’ll have to wash with lots of dishsoap and water once you have dumped the bleach mixture. Depending on the type of container the bleach smell will dissappear immediately (glass) or in a few days if left open to the air (plastic). Good Luck!