There seems to be a few misconceptions out there about turbulence/ cleaning cabin /LoCo airlines.
First, the turbulence encountered will not know if you are a full service carrier or LoCo.. You can still get bounced all over the place.
matblack - Cabin crew are NOT trained to move around the cabin during periods of turbulence. This is a matter of common sense, if there is a safety need for the crew to be on their feet then they should be, the primary reason for them being there is the safety of passengers. If there is no safety need then they should be sat down.
Easybaby - Cabin Crew may be well able to judge if they are able to stand up/move about in the turbulence they have just passed through but they cannot judge if it is safe to move around during the turbulence they are about to encounter. No one is! The seat belt sign is YOUR clue that things are going to get lumpy, check the pax and SIT DOWN!
If I were pax on an aircraft, seat belt signs on and some crew member swatted me in the ear because he was cleaning up the cabin I would sue the arse off the airline. The only reason he would be cleaning up is commercial ie. to speed up the turnround. It is SAFETY that is paramount not the commercial requirements of the airline!