Can I interrupt the cleaning operation once initiated?

It is important to note that Clean up is generally a quick operation with not enough time available to interrupt on most occasions. However, while cleaning operation is in progress, trying to close the window (Cmd+W) or quit the Application (Cmd+Q) will bring up a confirmation alert to either Abort or Continue the operation. Also, it is important to note that aborting clean up midway may leave the clean up in a partial state and hence you are advised to do it only if files were inadvertently selected for deletion with no backup available.