RE: PVC Pipe boxstand??
If it is that big inside, just get a drywall bucket with lid and do your biz in that. Snap the lid tight and no worries. You could even put some rv toilet deodorizer in there and it would last long enough that you wouldn't have to empty it every day.
I'm not sure the pipe is gonna be ridgid enough. Go to a home center and lift a 12' length and see how much deflection it has. I think if abs or pvc pipe was good for building things with, we would be living in pipe houses.