Hi! I ended up here because of your heading "single firing an electric kiln to ^6! I used to visit your area (Antietam and Shepherdstown) frequently when I lived in Maryland. Now I live on an island 10 miles off the coast of Maine where electricity costs 70 cents a KWH!!!! Unfortunately I am addicted to making ceramics.
Luckily I can sell my pots through a co-op here in the summer. Between costs for boat freight for clay and electricity, I don't know if I could afford to sell at wholesale.
As you can surmise, it would be fantastic to be able to save a firing for each piece. Did it take you a long time to figure out how to successfully once-fire?