I am trying to think and essentially boycotting say a large car dealership owned by a mason or any business that affiliates with any masonic lodge.

If its just a random mason then calling the theology of masonry like obedience and stuff that would encourage people to get out.

If they are doing any sort of gesture ask them why they are holding their arms like that etc.
"why are you doing that with your hands"

if you are in public and you shake their hand say something like
"what are you doing to my hands"