What does it mean when you dream about falling into a dirty pool with a frog?

That depends on the type of frog you are dreaming of and what activity the frogs are engaged in during the dream.

To see a frog in your dream, represents a potential for change or the unexpected. The frog may be a prince in disguise and thus, signify transformation, renewal or rebirth.

The frog symbolizes uncleanness or fertility. To see frogs leaping in your dream, indicate your lack of commitment. You have a tendency to jump from one thing to another. It may also suggest that you are taking major steps toward some goal. It parallels your progress. To dream that you are catching a frog, signifies your carelessness concerning your health. To hear the sounds of a frog in your dream, indicates that you have not accomplished what you wanted.

To eat a frog in your dream, represents some unsavory or unpleasant task that you need to perform. If you swallow a whole frog in your dream, then there is something that you need to do or say, that is literally difficult to swallow. Consider the phrase "a frog in your throat" to suggest that you are unable to speak. You feel you have lost your voice.