Complex sentence: The most widely used is known simply as "throw-and-go": the patching mix is thrown into the pothole, on top of any debris or water that may be present, and is compacted with a shovel by manual labor.
Split into simpler sentences: The most widely used method is known simply as "throw-and-go". The patching mix is thrown into the pothole along with any debris or water present and compacted with the shovel by manual labor.