I would say "Each side <desginated person> Ripple The Wave" if I wanted it done on each side.
Technically, Ripple is a 4-dancer call unless the word 'Grand' is used, hence if the call was "<desginated person> Ripple The Wave" then that person stays within the 4-dancer formation and does a Ripple 2.
Of course, from a Caller's standpoint, you should strive to be unambigous whenever possible. Adding words such as "Each Side" or "Grand" go a long way in this respect. It also helps if you indicate the number and direction for the first arm turn (e.g., Grand Right Ripple 4).
