I don't believe much those sellers that claiming the methods as their own but the truth is not, I think they have just got it from the internet shared by generous geek guys maybe on other forums and blogs. There are really lots of them so always make a background research, we can learn by self study.
I think this is correct, many of the methods are not original and it is something they just saw in another forum and they are trying to earn a quick buck, that does not mean the method may not work but since they have not tried the seller will be of no help if you run in trouble.