I'll explain my comment:
They will work, but are not designed to be used for HT. They are made to bake slow and long. Big units are more usable than small ones. Many require 40 amps at 220VAC.
For firing pottery, as I remember 1800F is barely enough for normal clay baking work. It takes a bigger and hotter oven to vitrify glaze and fire earthenware.
You gave the specs as 110VAC and 1800F max - That isn't a big one. The first of the problems comes from the depth not being sufficient to hang blades. Opening the top to put in and remove blades is not a pleasant (or safe) thing. Most folks make a hole in the top and suspend the blades on 1/8" stainless hanger hooks. They put a fire brick or layer of insulation over the hole.
Most likely you will need to make a pottery kiln PID controlled, as the temperature control for a knife HT and a pottery firing are far different things. This isn't hard to do, but adds about $100 to the cost.
Additionally, the last 200-300 degrees on the pyrometer scale dial are like the last 30 MPH on your speedometer. You are unlikely to get there easily. I found most 110 volt devices that have a scale reaching 2000F will go to 1800F max. Ones rated for 1800F usually get to 1600F reliably. Because pottery kilns are designed to take pottery from cold to as high as the fusion point of the glaze ( around 2400F), they are massively insulated, and minimally heated, they heat up slow to allow the clay to slowly change. If you open the oven while hot, the temp will fall, and it takes a while to come back up. The big kilns have sufficient thermal mass in the thick refractory to keep these swings smaller, but the small hobby kilns can take a good while to return even 50 degrees. Knives require a pre-heated oven, so we use faster heating coils. If the temp drops, they rebound fast.
I say if the price is below $100, get it and play around. Add a PID controller. At the least it can become a small tempering oven.
I took one and cut a 4" hole in the top. I made an 18" salt tube from heavy walled 4" OD stainless pipe. I have niter salts in it for low temp salt quenching and bluing hardware and damascus. I wrapped two layers of kaowool insulation around the exposed pipe that sticks out the top of the kiln.
Final comments and summation-
Pottery kilns are not designed to be opened once hot.
They are not designed for rapid temperature changes.
They are made to be sealed up and run through a firing cycle that ends at room temperature a day later.
And beware ******** They are not usually made with door interlocks. That means the coils are powered when you reach in and pick up a blade. If the blade touches the coils you can receive a serious .. or fatal... shock. Your HT gloves will most likely protect you, but that is a chance I would avoid rather than take.
