You CANNOT stimulate hypertrophy of any different part of the pec. Your pec shape is determined by genetics. It will grow as one muscle. If that were true, you could grow huge "lower" pecs and tiny little upper pecs. That's not possible.
If you disagree, I suggest that you devote your life to doing that and when you have results showing it, post pics. Otherwise, I'm going to suggest science to these guys and not have them mislead themselves doing crazy **** to try to target different parts of their pecs.
This is all along the same lines as "shaping" your biceps, as in to widen them, make them peak more, or making them longer. The shape is determined by genetics.