Incidentally, I did not pay for Grime Fighter (and have no intention of ever doing that), I did not get the option to install or not - it just appeared on an update. I cannot find any way to disable it let alone uninstall it. I checked "licensing information" to find that there are no licences associated with my account! This is, at best, puzzling.
So, it was unasked for; on startup I am getting (what are meant to be) worrying messages about "Grime" and "bloatware" (even though none are reported! - work that out) as well as other claims about speed, but with no further information or options - no settings of any kind. So, dear Mr Uber-evangelist, how does this square with your statements
"Actually, you need to buy before you can use. It is not a free product. You also need to get in the habit of using the custom install and stop using default install." ?
You also make there an unwarranted assumption: my lifetime habit is of *not* using 'default install' - whenever I get the option.
This is, to coin a phrase, scaremongering foistware of the worst kind, as Danno said. We are in no position to judge whether it is worth giving it the time of day let alone whether it is effective as claimed.