Answer:
The sentence you provided doesn't have any major punctuation or grammar errors. However, for improved clarity and readability, you might consider a slight revision:
"Squidward Tentacles got so dirty playing soccer that he thought he would never get clean. In fact, he went through two whole bars of soap that night."
Adding a period after "clean" and starting a new sentence with "In fact" can help to separate the two related but distinct ideas, making the sentence easier to understand.