Really?putting something foreign into the stalk that induces stress during this period does make some sense to me
The only reaction from the plant that seems reasonable to me is that it tries to heal the wound, which has nothing to do with resin production.
If you want to increase resin production, then you should find out what the resin is used for in the first place, and I can tell you it's NOT for fixing wounds in stalk because some dude drove a chopstick / toothpick / whatever through it....