Hello!
I do quite a bit of dowsing myself, and was fortunate enough to learn from a man for whom dowsing was a profession! However, last year I did some dowsing lessons for the coven I run, and wrote a short outline of the procedures in order to help aid them. I have attached it this reply for those interested.
As a side matter, I personally find that a pendulum can be anything, it makes no difference what it is made of, I've even dowsed with a teabag on a string before! The pendulum itself seems to act as an amplifier of the small movements that your arms/hands make, turning them from a subconscious jolt, into a recognisable movement. This is why it is necessary to train the responses to match their meaning.
To do this simply choose the responses and say them as you re-enact them. Mine are as follows:
Swinging backwards & fowards "This is the neutral position, it is searching."
Swinging clockwise "This is positive, it is yes"
Swinging anticlockwise "This is negative, it is no"
Swinging diaganaly "This is maybe, it is undecided"
This needs to be done several times a day for many weeks to set your body up to produce certain responses for certain answers. It is much like tarot, you shouldn't expect to be able to just pick it up and be an expert with no practice (although some are lucky like that!).
Back onto the subject of pendulums themselves, I first had a brass one that I adored, I really thought that I wouldn't be able to dowse with anything but this pendulum. After a year it went missing, and I could never find it, not even using dowsing! I am convinced that this "mislaying" of my prized pendulum was a way of forcing me to dissolve my reliance upon the prop itself.
By way of interest, the attachment has a bit on L-Rods, you can make these out of coat hangers. Just cut the top hanging bit off, then cut in the middle of the long bottom bit, you should then have two L shaped rods. You hold them with the longest point outwards, gripping lightly in the hands, as if they were guns!
Anyway, good luck, and perservere,
Love & Light,
Martin