I have seen over the inter webs different apps that claim to do this process, whether app clean or UninstallPKG, but I can see these things being dangerous in some hands. Now you have all the places where the plugin is installed as well as the related system files! You can now delete everything (with some caution of course).cool, didn't know this as well! If 'System Files' are not included as an option in the drop down menu select 'Other.' and add them. Then use the cross sign at the left to further expand your options and select 'System Files' and 'are included'.
In the Search line below select: 'This Mac' and 'Filename'. Open Finder and type the name of the plugin at the top right search area.
