Controlling/Stopping Certain Dreams

I'm new to dream research, and don't know much about LD except the seeming objective of "realizing you're dreaming during dreams).

From what I've read so far, dreams are products of the subconscious, revealing life's daily experiences. I've also read that in controlling what you dream, you should think about the subject (what you want to dream about) before going to sleep; this is supposed to enhance the chances of dreaming about the particular topic.

My question, however, is about preventing certain dream topics, such as those which would bring about stress.

It's been my experience, when having repetitive, and unwanted, dreams about the same topic, bringing the topic into the conscious, before going to sleep, prevents the dream. This seems to be a good way to stop dreams about topics we don't want to dream about.

Is there any credence to this method in other's opinions? Is this a known method of relieving bad dreams?

Thanks