The bottle cap is an item so common, that often we pay no attention to them whatsoever. They constantly surround us, at home,
in bars, in supermarkets, alleyways, and carnivals, and only rarely will one give a thought to the pain that so simple an item can
produce.
The primary use for the bottle cap is for it to be inserted under the skin. A fairly small incision is all that it takes to fit this item
inside. Unless your intent is special, it is probably best to not tear the skin unnecessarily upon insertion, the idea being to build
up to a level of pain, not start off with excessiveness.
Once inserted, it can be pressed, beaten, or even twisted from without, and this is where the method really shines. The rough
points of the bottle cap nicely abrade the delicate nerve endings inside the flesh. A personal favorite is to insert several under
the skin of the subject's back, then binding them in such a way that they are forced to lie with their own weight upon the bottle
caps. Occasional nudging is sometimes required to keep the subject from becoming too accustomed to the pain ofany one
position.
Tempting as it may be, avoid scraping or sawing through the skin with the bottle cap itself, gruesome as it may seem. There are
far more economic ways to spend your time, and this is the mark of an amateur.

Areas to consider:
--Under the eyelids. Once inserted, rarely is any additional pressure needed, as the motion of the eyeball scraping against the
sharp edges is cause for plenty of agony.

--The testicles, penis, vagina, or anus. With the former three, some additional pressure or movement will be necessary, but
produces wonderful results. Experiment with folding the bottle cap as well. Often the elongated shape with just two pointy ends
will prove a much better fit in the genitalia. For the latter, it is not the insertion which is going to be the most painful, but rather
the expulsion later by defecation. Try to insert them with the flat side first, which will position the crimps for maximum
scraping/snagging on the way out.

--Elbows or Knees. By placing the bottle caps close to the major joints, you can avoid having to apply as much pressure simply
by bending the subject's extremity. The motion of their own skin and muscle does the work for you.

Supplemental practices:
When time has not been an issue, it has been known to happen where the entry wounds for the bottle caps were sewn shut. With
only a couple of days of "rest", the wounds heal closed to a certain extent. This leaves a great possibility for infection, and even
more pain, not to mention that the subject can them be moved around without fear of them removing the caps easily. A word of
warning however, as will any infection, should it become too great the subject may fall prey to delirium, and this can have
unpredictable effects on the outcome of your inquisition