Hi Vito, here's what I do:
Dry curing black olives in rock salt
How it works:
The rock salt pulls the moisture out of the olives, concentrating the flavors.
What you want to achieve:
A condition in which the rock salt and olive mixture are in a container that will allow the moisture to drain away
What you want to avoid:
the rock salt and olive mixture spoiling because it is sopping wet [because the moisture is not allowed to drain away]
Possible setups:
Simplest:
Rock salt and olives in a burlap bag, set this inside a cardboard box that has been lined with a garbage bag, with newspapers or other absorbent materials between the burlap and garbage bag. As the moisture drains into the newspapers, toss them out and replace with dry newspapers
More involved:
two 'nested' bin containers, for example like the following: http://ecx.images-amazon.com/images/I/41nThI69rBL._SL500_AA300_.jpg
The upper container needs holes in the bottom so the moisture can drain away and collect in the lower container (when the containers are nested, there should be at least an inch of space between the bottoms of the two containers).
Process
1
Make alternating layers of rock salt and olives [make the bottom and top layers rock salt]
2
Every few days, shake or move the container so the rock salt and olive mixture is redistributed. Because olives are less dense than rock salt, some will come to the top. Cover them up with rock salt.
3
Also every few days, check to see if there is any collected moisture. Clean it up [change newspapers or dump bin, etc.]
4
When the olives are shriveled to about what's shown below, try them.
http://independentvisions.org/fichera/af/images/olives-moroccan-dry.jpg
If you want to leave them in the rock salt longer [to further concentrate the flavors], please realize that the salt will continue to pull out the moisture until there is very little more than the pits and a tiny covering of olive pulp (this happened to me a few years ago because I had to be out of town unexpectedly). So, don't forget about them!
5
When remove the olives from the rock salt, wash and let dry. You can store in the refrigerator.
I cannot tell you how long they last because they are in high demand by family and friends that they disappear immediately!
(I gave out my entire last batch at the memorial service of my dad's best friend...he cured olives with his dad when he was small.)
They're great when mixed with a little olive oil and some spices like cumin.
NOTE:
I don't reuse the rock salt for more olives, but since my family and friends make so much home made ice cream, we reuse the olive rock salt for that purpose.