To answer your question, first, we need to understand why the water is building up in the first place.
We live in the south, and from June through September, it's hot and humid! All that not and humid air is trying to make its way into your home. Your clothes dryer has a nice vent with a 4” opening to the outside. The cool, dry air from inside your house makes it's way out, and the hot, humid air makes its way in. When the hot, humid air meets up with the cool metal parts of your dryer, it condenses and turns back into liquid water.
The reason water was NOT collecting inside the dryer is that prior to cleaning, the dryer vent was COMPLETELY CLOGGED, and this prevented the warm moist air from coming back into your home.
Don’t worry to some degree; this is normal. There are some things that you can do to help minimize the moisture build-up in your dryer, but it might not be possible to prevent it.
Things to check:
Does the cap on the roof or side of the house open and close freely?
Does the cap on the roof or side of the house seal tight when closed?
Inspect the dryer vent ductwork. Are all the seams and connections sealed and properly taped?
Keep in mind that when it's 90df and 90% or higher humidity, it is very difficult to prevent moisture from coming back into your home and condensing back into liquid. Even if your dryer vent is %100 correct and built to building code, you might have some moisture build-up in your dyer.
Things that might help:
Remove the closes from the dryer immediately when the dryer completes the drying cycle.
Leave the dryer door open when it's not in use.