I tried a few methods that I read about such as using a crock pot with water in it to provide heat and humidity to an insulated box. I did all sorts of things but could never keep the humidity high enough for some reason. I ended up using a box made of Styrofoam and a light bulb for heat. I sprayed the leaves and put them in plastic bags to keep them moist. I would check them every week to rotate them around and make sure they were moist. I controlled the temperature by leaving the top of the box open a bit. It took a couple of months but it was easy once I got the setup working.
Prolly depends a lot on where you live. In the tropics, as I understand it, they just dip 'em, pile 'em, and away they go. In Ontario, you start out so much cooler, and soon as you heat the air, it gotta get that much drier. Here in Dull-Aware, we go hot and damp all summer, then this time of year it's suddenly chilly and dry. So summer ought to be a good time to cure leaves here. FX Smith is in a place that's higher and cooler than here; but he makes his maduro in a cool basement by some secret method he won't say. Tells me it only takes, what'd he tell me, 3 days, 5 days. He's curing maduro for a cigar maker in the Dominican now, last we talked. Guy says he wants to buy Smith's secret, but Smith says show me the money, is where they are now. The guys at FTT are mostly curing in old fridges, from what I read; tho there's one guy simply puts his leaves in a bag on the dashboard of a derelict pickup in the yard. Gotta love that. That's my kind of practical.
But here's one thing puzzles me: You say you ferment to REMOVE ammonia. But isn't the fermentation exactly what MAKES ammonia ? Need a DIY geek to chime in here and settle the matter. I know for certain that if I put wet leaves away in a sealed bag they will start smelling like a diaper pail. I know when Smith pulls his wrapper out of the secret basement curing room, he spreads them out on a big floor in front of fans to blow off the ammonia. I'm saying I think you got that backwards. Fermenting creates ammonia, does not remove it.
I've used pale-colored raw CT shade ... no ammonia. Course, I've used fermented shade as well. My new fave wrapper is that EC seco shade from LO. That stuff's dark. I assumed it was fermented. My all time fave, tho, is the Habano 2k I used to get from WLT. Tan colored, about like this KY Sumatra, just less yellow. I assumed that was not fermented.
Anyway, I'm too lazy to ferment. Rather go wrench on a motorcycle.