For years all I used was a mokapot (I had quite a collection, but I passed most of them on). The 3-cup size worked the best for me, and as the Goat Guy pointed out, they need to be kept in regular use for proper functionality. I never used detergent, just rinsing them out quickly after they cooled and brushing the seal. What I found was that the grind was the really important part - a blade grinder is insufficient - you want consistently sized grounds and they shouldn't be too fine. The coffee needs to be loosely packed (if you tamp it you will have big problems, see below). It takes some time to develop a consistent process, but when done right you will actually get crema and an extraction that runs about 45-55 seconds. I always heated up the electric burner to medium-high, then placed the loaded mokapot on it. It would usually take about 2 or 3 minutes for the extraction to start.
This was a daily ritual, and I used to make beverages for my wife and I before leaving for work every morning. One morning, however, I nearly wound up in the hospital... I had set up the mokapots and put them on the burner as usual. I had placed my milk steamer on another burner, as I did every morning. About a minute into it, I heard the buzzer on the dryer go off downstairs, and breaking my usual procedure, I ran down there to remove my shirt. Right before I got back into the kitchen I heard an explosion, and walked in to see that the top of one of the mokapots had blown off. There was black coffee literally painting the ceiling and walls around the stove. Further investigation showed that three factors caused this:
1) The pressure relief valve on the lower part of the mokapot was scaled over with lime, preventing the release of overpressure.
2) Some retard had dialed the grinder down to a much finer setting (wonder who that was...)
3) The basket was probably slightly overpacked. [I used to carefully pack in an attempt to get about 4 atm pressure when extracting. This is a no-no]
The explosion occurred when the screen above the basket literally ripped in a semicircle allowing sudden release of pressure. After this experience, I was much more cautious about checking the pressure relief valve and not grinding too fine. If I had been standing in my usual attentive position in front of the burner, I would have been scalded with steam and grounds.
My love affair with mokapots ended when I bought a Saeco Gran Crema, which made decent shots without so much daily cleanup. I gradually passed most of them on to less fortunate individuals that had no means of making espresso-like beverages at home, although I still have a milk steamer and a couple of these for camping.
BTW- mine were all aluminum, and I believe that regular use allows a coating of the device with coffee oils. If they sit around not being used, the oil goes rancid and gets bacterial growth. Then the product can be pretty rank tasting. When I used them every day they seemed to get better and better.
