I second the Dragon's Blood. You can burn the commercial incense or the straight resin. The straight resin generates a LOT of smoke, which is unfortunate, but has a very pleasant, almost delicate, subtle smell I really like. It's slightly spicy but sweet at the same time. Sage is a great purifier but smells like weed, which may or may not be what you want.
You know enough about magic to do banishings, etc. Regular cleansings are always a good idea, pesky ancestor or not, just to get rid of all the astral gunk we make and carry around from day to day. It's no different than housecleaning, really--and every now and again you might find something of great value buried in all the crap you've got lying around. I know I do sometimes.
As the water grinds the stone,
We rise and fall
As our ashes turn to dust,
We shine like stars...