I had to edit around 4~5 .cpp files but now it is working like a champ. I created a function in C++ to delete the table rows for that NPC and made the companion PERL function and it works like a champ. One step closer.

Okay one last thing, I can clear the merchant's inventory in the database but it does not seem to reflect the change until the zone loads again. Is there some way to make the merchant reread the table?