Scruffy hit the nail on the head, at least for what happened to me (the 'plain mean')
Lets just say I had a massive argument, and it caused problems for my LD's for a while

That doesnt mean it *cant* work... some people strike deals with their subconscious for other skills (besides LDs)
In theory, it can work, if you can get agreement and friendliness

[EDIT]
Oh yes, and like Scruffy said - theres that little problem of not knowing if its really your subconscious manifested
I honestly dont know if mine was ...