How to make a messy kid clean a messy room?

Sometimes, I don't understand how others' homes with kids can always be clean and tidy. I don't want to admit it because I am lazy. The truth is I am too tired to clean every day. I try to let my 3-year-old boy clean the toy room because he always makes the room messy.

Mommy: Please clean the toy room. It is too messy.

Son: Mommy, I am tired. You clean.

Mommy: I can't clean today because I am sick.

Son: Mommy, I am sick too.

Mommy: Ok. You are sick. You need to see a doctor. No chocolate, no ice cream, no candy.

Son: No, No, No, No. I am not sick.

Mommy: Go to clean.

Son: Ok. Mommy, you sick. No chocolate, no ice cream, no candy.

Mommy: of course.