Blog commenting isn't worth a piece of shit, Page Rank means shit, work on your own sites and internal linking to your own relevant content is far more efficient - why people still use these techniques that were OK 5 years ago is beyond me.
It's always a risk that all the work you put into a blog comment may not be approved, which is why it is always a good idea, to ensure that the comment adds value to the conversation or it might be removed
Blog comment is one of the best way and to get a quality back link from a site and if blog is do-follow then it will be great to have your link there.
you can try this strategy, but dont sure that it will give you a good results if you will use special software.