I have instructed fairly widely in both Cessnas and Pipers in a variety of seasons and locations. It is very difficult to make a generalized statement about the use of carb heat for either aircraft due to massive number of different models, many of which have since been modified. It is an exceptionally good idea to do whatever the aircraft handbook says. I personally nearly killed myself and an unsuspecting student because of being too lazy to read the handbook early in my instructing career, on a different issue in a new to me aircraft.
If you must have a single procedure for all piston aircraft, then by all means use carb heat for a full minute before your power reduction, and remember to lean appropriately (which may mean not at all). But it is better to fly each aircraft as it was designed to be flown.