I only posted that as one option. 'Surround speakers' being a relative term, it's only a matter of time before someone would try to hang a pair of floor standing speakers the way I described, so I should qualify this with:
"Use the maximum weight guidelines stated by the maker of the clips before hanging anything heavy". It shouldn't be necessary, but if they need to put "Not to be used in the shower" on an electric blow dryer,....
How the speakers will be hung depends on the desired look. If space allows, making a shallow plywood box and covering it with ceiling tile pieces, cut to fit, decreases the "look" of hanging speakers. If it has to be flush, heavy speakers should be attached to the structure.