100% clean using the official apple's method: The bootable macOS installers created with this tool are made using the official apple's createinstallmedia method, just as if you created them using the command line, this ensures the best and the cleanest results avoiding all the problems that modded installers have.
Integrated downloads from Apple for lots of macOS/OS X installer apps (to access them open the app, go to the menu bar, and then ToolsDownload a macOS installer).