I built a cradle to set my stave on top of a big canning pot like you would can vegetables in and then wrap aluminum foil over top of the stave to keep the steam in. It's worked fine, but I like the stove pipe idea better. I do steam now and then with green staves to work out a few kinks before sealing them up, but I agree with DVS about the dry heat and I use that more than the steaming. It's also been my experience that even though I steam out a problem area when the stave is green, within a few short weeks it's contorted itself again as it dries so I end up using dry heat in the end anyway.