[MMM]

If you have studied Japanese seriously for a few years this can be an excellent way to supplement your knowledge and fill in the gaps with some more modern/slangy Japanese and kanji you wouldn't normally see in a textbook.

However, if you do now have a strong foundation to start with, you are really just reinventing the wheel, and doing it the hard way. You will be trying to break a code that has already been broken many times before. Also, without the foundation of Japanese study, you won't know what is slang, what is Kansai-dialect, etc.