No antivirus, no matter what brand, is 100% guaranteed to remove everything there is. iSearch. SafeFinder is adware, more of a nuisance than a virus or trojan, and the guide you have linked above would be what we would recommend here.
Always be on the lookout for 'extras' when downloading and installing or updating anything.
McAfee cannot delete 3rd party Applications, as maybe some users would like to use it. It is responsability from users to check what they are installing. You can use your antivirus (customizing) to prevent those programs to get installed with functionalities like Access Protection or the equivalent in Home Users products.
Unfortunately the Home products are a bit limited in that regard.
The "Access Protection" feature in SecurityCenter > Navigation > General Settings and Alerts is limited in scope.
Due care is the best defence.
You may find these two articles most informative : PUPs - Potentially Unwanted Programs - Basics
Here is another Removal Guide by the same Reliable/Reputable Specialists:How to remove Adware:Win32/ISearch (Removal Guide)
You will notice Malwaretips.com recommends some of the same Superb Free Tools,as you will find in that Link that Colleague Ex_Brit Inserted.
All the Best
McAfee Community Moderator