It would seem easier to educate the users to use that option (no longer in Safari 8) than to send them to Self Service?
Otherwise, I have an old list from a thread on the Apple forums that lists the files you can manually remove and it would be easy to script it, adding or removing items to fit your needs. Would be mostly version-proof too I'd guess.
Maybe you could even try lines below one at a time to see what might be needed without blasting it in total?
mv ~/Library/Safari ~/Desktop/Safari-`date +%Y%m%d%H%M%S`;
rm -Rf ~/Library/Caches/Apple - Safari - Safari Extensions Gallery;
rm -Rf ~/Library/Caches/Metadata/Safari;
rm -Rf ~/Library/Caches/com.apple.Safari;
rm -Rf ~/Library/Caches/com.apple.WebKit.PluginProcess;
rm -Rf ~/Library/Cookies/Cookies.binarycookies;
rm -Rf ~/Library/Preferences/Apple - Safari - Safari Extensions Gallery;
rm -Rf ~/Library/Preferences/com.apple.Safari.LSSharedFileList.plist;
rm -Rf ~/Library/Preferences/com.apple.Safari.RSS.plist;
rm -Rf ~/Library/Preferences/com.apple.Safari.plist;
rm -Rf ~/Library/Preferences/com.apple.WebFoundation.plist;
rm -Rf ~/Library/Preferences/com.apple.WebKit.PluginHost.plist;
rm -Rf ~/Library/Preferences/com.apple.WebKit.PluginProcess.plist;
rm -Rf ~/Library/PubSub/Database;
rm -Rf ~/Library/Saved Application State/com.apple.Safari.savedState
