So far everything seems to be fitting the definition.
Someone suggested to me that there is a method of fermentation using a kiln:
"This is what the smaller grower must use if he or she wants to smoke the fruits of their harvest any time soon. The kiln is a small, insulated container with an artificial heat source that helps to simulate the fermentation. The leaves are placed in the kiln with the lid shut. Heat and humidity are carefully controlled (temp 100 to 130 degrees and 65 to 70% humidity), and the kiln is left on 24 hours a day. Kiln fermenting lasts about 4 to 6 weeks and the relative humidity must be carefully maintained during this time. A short aging period will follow of 4 to 6 weeks or longer until the leaves can either be rolled into cigars or cut for cigarette, pipe, or chewing tobacco. "
The same person thought that this:
http://www.seedman.com/wkiln.htm might be what I am looking for.
There seems to be a discrepancy in dictionaries. Here are three definitions for a sweatbox, taken from three different dictionaries:
1. a device for
sweating something (as hides in tanning or dried figs)
2. a device for causing
tobacco leaves, fruit, or hides to
sweat
3. a device for removing moisture from
tobacco leaves, figs, raisins, etc.
So twice we have sweating mentioned, and twice tobacco. The second one seems to be about fermentation, the third one about drying, and the first doesn't mention tobacco, so I can't be sure.
There is also a definition of the verb 'to sweat':
: to cause to exude or lose moisture; especially : to subject (as tobacco leaves) to fermentation
I think that I need to find out what does it mean to sweat hides or dried figs. I have no idea whether fermentation might be a part of tanning and it doesn't seem to make sense ferment dried fruit. Maybe that would lead us in the right direction.