I found a nice way to use them. Position one team in front of two open doors after you are sure the OPFOR will not simply step into the line of fire. Place them on hold and give them paths to enter. Then have Team #3 standing on the other side of the door entrance lob in 4 flashbangs. On the final lob, hit 5-key to have your two teams go in. This seems quicker and more efficient than lobbing and entering yourself.