First, I just want to say that I did not have a rubber duckie when I was a kid and that makes me sad. Second, do kids these days still have ACTUAL rubber duckies or are they digital and teach them their colors now? If you kid DOES have a rubber duckie then most likely it is filled with tons of bacteria.
Researchers cut open a bunch of rubber duckies (the HORROR!!!) and found a ton of bacteria inside them. Almost all of them had “murky” water inside them that was housing fungus and bacteria. The majority of them, 80%, had bacteria bad enough to actually make people sick.
So other than be disgusted, what can you do? Throw it away. Throw it away RIGHT NOW! You can either replace it every 6 months or buy a more expensive one that has a higher quality of polymers.