Cleaning toys that spend time in a soapy bath may seem unnecessary, but the moist environment makes way for breeding mold and lots of unwanted soap scum. Instead of throwing the toys away, disinfect them so they can be enjoyed.
Start by selecting any rubbery toys that squirt water, which are more susceptible to retaining water and growing mold. Clean the inside of these toys with a concentrate of 2 cups of white vinegar and 5 drops of tea-tree oil to disinfect (adjust the volume ratio if you only have one toy, or have a dozen).
Draw the solution into the toy, and allow it to sit inside the toy for 15 minutes. Agitate periodically to help any mold and gunk loosen within.
After some time has passed squeeze the liquid out of the toy.
After cleaning, if you can still see black mold inside the toy, toss it. The vinegar solution is great for regular maintenance and prevention, but there comes a point when it's hard to guarantee that all of the mold is removed.
To clean the outside of the toys, combine 2 gallons of warm water, 3 tablespoons of natural liquid dish soap, 5 cups of vinegar, and 10 drops of tea-tree oil into a plastic container. Snap a lid onto the container, and shake-shake-shake to mix it well. This solution is less concentrated than the mixture you used in Step 1, but very good at removing soap scum. (It also makes for a wonderful all-purpose cleaner too, should you decide to store some in a spray bottle for those times you want to clean your kids toys!)
Add all of your bath toys to this solution, snap on the lid, and shake the container more so that the soap in the solution agitates and bubbles and envelops the toys.
After a minute or two, open up the lid and check a few toys. Has any evidence of soap scum loosened? Is the outside of the plastic toys squeaky clean?
Continue to shake the closed plastic container until the bath toys are sufficiently bathed.
Drain all of the water right into your bathtub. Fill the container with water from the spout the rinse residual soap from the toys, and then then lay them all out on a flat towel to completely dry. Be sure to squeeze any of those toys that squirt water – after cleaning and after every bath use, they should be emptied to prevent water from sitting inside the toy.