People, you can sell them in your invo. Really! I keep seeing them in the MP for less than 1/2 their value, which is nuts. (A sweet way to make a profit, but the holiday spirit in me slapped me upside the head for such thoughts. Bad me.)
Click your avi
Click Full Inventory
Click organize your inventory (has to the be invo arranger)
Select the house tab
Select whichever tree you have
Now click the sell item button, and it'll ask if you really want to sell it for 1/2 value. Say yes.
Hope that helps anyone who didn't know how to get rid of the infernal things other than the MP!