Private entities banning guns on their private property is not the new gun control. I am not aware of any organized effort in getting private entities to disallow guns on their property other than the typical liability-lawyers and those private entities with an agenda.
As I said in an earlier post, take your boss and coworkers shooting. Show them how fun it is. There are multiple posts on this website on how to do it (a few tips, don't talk politics or self-defense at all and make a show of safety) effectively.
Boycotting and open carrying probably are not the best ways to go about it.
gtalk:renfes steamID: Sefner