I guess I should have looked down here before posting a hello to your intro post. =)
The only time I have done a smudge (had someone with experience come and do it with me) to try and free a ghost that was bound to our previous home it was done with 4 things - sage, cedar, sweet grass and tobacco. Well it turned out the fellow did not want to leave and did not like our trying to get rid of him so activity increased.
I agree with Nakis it is a very nice thing your wanting to do something. I also agree with Kevin that if a ghost is hanging about, taking down the building they are in will not make them simply go away. Shoot many ghosts are linked to buildings that were on the land (or the land itself) long ago before the one they are currently residing in was built.
I like your comments on following your heart and do what feels right. =)