I suggest Piroform cover the family's computers for home users purchasing the Pro version. While $25 may not seem like a lot for some people, the typical family in the USA has 3 computers and will not pay $75 for a CCleaner license to cover all 3 computers. I believe that the end result would be more sales for Piriform as more families would purchase the Pro version for scheduling & multi-account cleaning rather than use the free version.
I am currently checking with development on whether the license is limited to a single machine install
CCleaner Professional is licensed to a person, not a machine. Can be installed to any number of machines as long as it's personal use and the buyer's personal use
If there is only one person with Admin authority and the personal ability to run CCleaner on all the family computers,
are the other family members allowed to enjoy the benefit of running standard non-admin profiles on those computers ?
pro version allows cleaning of a user's own files, multiply selected users, a non-logged user or all users. Thus admin can clean non admin files