I've been busy building a special container to clean some of my wafer irons. The old long handled, hearth style irons. They can be over 2 feet long.
With lye, it doesn't matter if the whole piece is immersed, it will clean, then you just stick the other end in and it will clean up just fine.
Both EvapoRust and Molasses will cause problems if the whole item is not immersed in the liquid or there are places that gas bubbles can form. A permanent black line will be created where the liquid ends (bubbles look even worse). A work around that I've used is to hide the line at a corner or joint.
I always am careful to make sure there are no places for gas or air to get trapped when using these liquids.
A person could lay a long item down flat in a tub, but it needs a big tub and lots of liquid. Cheap with molasses, pricey with EvapoRust.
A few years ago I built a cleaning tube from 3" drain pipe that worked well with my lye.
So, I went looking and found a 2 foot lenght of 6" PVC sewer pipe at Lowe's. Found a cap on eBay and finally glued it all together.
But, surprise, as you can see, my wafer iron is a bit longer than my finished tube (by the way, if you look at the balls on the handles they indicate a German or Northern European origin).
So I figured I would just add a coupling. Well, 6" pipe fittings are not something that you find at your local big box store, but I did find a neoprene coupler.
I've attached a few pictures to show what I did.
Tom