Removing Cleanup Component
Open the Avast User Interface
Select Menu (Top Right) > Settings > Components
Scroll down to Performance > Cleanup > Uninstall Component
Reboot.
This removed the Cleanup utility from Avast. That isn't what was requested. Is there a way to disable Avast Cleanup from starting on Windoze start? That is a completely different option from "just remove it" as an answer. If there is no way to stop this from starting on Windoze startup, then this acts like a virus, not a utility, and Avast is not a product that should be used.
While I like the utility, I don't want it running all the time and certainly not on system startup. As the user and system admin for my computer, this is my decision to make, not Avast's.