I have something for the ghost thing! In anime canon, people observe Obon as well, most especially Toro Nagashi aka placing lanterns on water and letting them float away. It was successful in leading a Gastly away from the place, though I think it wanted to go anyway. I forget the exact circumstances of the episode but I think a Blastoise/Venusaur fusion was involved.

Since Lavender is connected to the bridges in the south, Toro Nagashi could work, with people building their own little boats or floaters for the lanterns.