What's you heat source? I found that the kitchen stove produces way more heat than a hot plate and thus way more steam.

I use a aluminum Leader (gutter & leader) section with a wood plug on one end and just stuff a rag in the other. It sould be no longer than the longest rib. I suspend it over some bricks on the stove with a kettle under it firing into a hole in the center. I have no hole other than the one on on the bottom. I use an old tea kettle from a junk shop that I soldered in a plumbing fitting with a 1/2" piece of copper tupe that extends into the leader. Once the stove is going it's really belting out steam and the leader and wood is really hot. I suspend the rib on some thru-wires like the others.

I pick up the leader with the rib in it and carry it downstairs and pull out the rib just before bending. It drips - but I just sponge up as I go.