Learning American Accent in very short time ?!

Hi there guys

I've been doing a lot of searches about American Accent and I have a question that I need answer for, there are online american accent training websites that teach the american accent in a very short time, for example 12 hours of one to one tutoring and including the materials such as the audio tapes and the cds, my question is, do you guys think it is possible to learn an accent within 12 hours??

Thanks

You might be able to replicate the accent after twelve hours and use it when you want to but I seriously doubt that it will replace your original accent. Only one way to find out though.

Not even Bernard Show was able to do that fast.
You don't really have to believe everything that's said online or in media in the US.