I dry my FB prints between archival photo blotters, they come in sizes of 17"x24" so are just large enough for 16"x20" prints.
Washed prints have excess water removed then blotted until damp. They are then stacked between 3 sheets of blotter, that is 1 print then 3 blotters until all prints are stacked. They are left like this over night. Next day all the blotters are replaced with fresh ones, stacked as before but this time left under weights (large portfolio boxes full of mounted prints) until completely dry within a few days.
They really do dry beautifully flat.
The downside is the blotters will need replacing every so often but they are relatively cheap. No heating is required other then normal room heating, so they are environmentaly friendly and the blotters can even be recycled
These are avilable in the UK from Silverprint which is not much use to you but I'm sure someone in the States must supply such items?