There are some words to say about the morality and attitude of the diviner. Of course, everybody has his or her personal reasons for dowsing. You want to find out something about yourself or the world. Or you primarily want to help other people. The range of application of a pendulum is varied.
But as reliable the pendulum answers may be, it should not compensate the own thinking. Some people exaggerate by making hardly any decisions any more without questioning the pendulum before. This is simply stupid concerning many everyday decisions. You should consider principally when it makes sense to use a pendulum and in which cases it becomes absurd.

There are also moral questions, which should not be decided by a pendulum but by common sense. I think, this must not be explained further. A pendulum does not substitute the ability of thinking.

You should always dowse with a good or pure conscience. This also means that we ask people before, if we want to divine for them.