That site does not remove the problem. The problem is Avast forcing ads on customers that are already paying them. They must know it bothers people. Severely tempted to try another company.
The link provided above is direction on how to remove components from your Avast Installation, of which 'clean up' is one of them.
If you want to pop ups for this component to stop then follow the instructions from the link and remove/uninstall the clean up component from your Avast installation.