I don't really think a clothes iron would work that well because of the shape. You can't just heat it and stick it in the form because you would just dry out the wood. The action of the water turning into steam is what allows wood to bend, so you'd need to be drying out the wood over the round shape of a bending iron to do that.
You can make a bending iron with one of the large 80watt soldering irons with an aluminum tube fitted over it. Or an aluminum tube and propane torch, but this takes more practice to get set right to not burn the wood.
There is a method called 'cold bending' used in violin making where the wood is wetted and put in a form, but violin sides are only 1mm thick and are maple.
There is also a 'steam box', where the wood is saturated with hot steam to make it plyable. Here is a link to one:
http://www.leevalley.com/wood/page.aspx?c=...176&cat=1,45866
I would think the steam box method may warp the thin wood in musical instrument sides, though.
I have a comercially bought bending iron, it's great. Before I used a soldering iron/pipe to bend my uke sides.