Many years ago, a couple and I went to visit another friend who had recently moved into a new place with his girlfriend. Older upper flat, good condition, hardwood floors, lots of nice woodwork, sparsely furnished. And then there was the tree in the corner. Fully decorated: lights, ornaments, tinsel, a star on top. Even had the little circular cloth thing below it to hide the stand. But no needles. Just bare brown branches and a bare brown trunk. No needles at all.
So we asked, What happened?
And Chuck told us that they had bought the tree a few days prior, and all the fixings, and decorated it that evening. He had heard that if you put an aspirin in the water the tree would last longer. I had heard that too; it was one of those sort of urban legends that would circulate; have never known if there was any truth to it. Unfortunately they didn't have any aspirin and it was late and the stores were closed. But Judy had some Midol and they figured, "That's close enough," and put a couple in the water before they went to bed. In the morning, they awoke to find most of the needles on the floor; what remained fell off as the day progressed. They swept up the mess and decided to let it stand like that since they didn't want to (or couldn't afford to) buy another tree.
They seemed a bit embarrassed. I thought it was kind of funny. And bright too - you could see all the lights, even those that would normally be hidden in the back behind the foliage. Which it didn't have. It was certainly memorable.
So if you ever want to totally denude a Christmas tree of its needles, that's how you do it.