Start out by straightening the nodes on one cane then set it aside to cool. Then straighten the next cane's nodes, and the next then lay them flat to cool. When you have straightened the nodes and they have cooled straighten the internode area. Sometimes you can only work a couple of areas on each cane then let it cool or the cane will go back to it's original crooked shape. You can't really rush the process.
Once I get my cane relatively straight I reheat each node and compress it by rolling it between the work table top and a flat hardwood block. I'll remove the thin corky ring around the node and re-straighten by hand and set aside to cool completely.