I know there are many cases to get prosperity, continuing cleaning the toilet.
The other day I got to know the “scientific” reason.
When people open a shop or an office, many spirits also move there together.
Every spirit takes a respective space there.
But fortune spirit comes late, because it moves very slowly with heavy gold, silver or other treasures.
When the fortune spirit reaches,there is only a toilet space left.
Other spaces are all occupied by other spirits.
So when you clean the toilet, the fortune spirit would be glad and give you fortune.