While I would never ever consider this option, I can see why few would, out of desperation. In your case, I don't see the absolute need for this.

First of all, this is not easy. Like Mexican said above, there are issues with it. You don't know what kind of party you're dealing with; they could extort you in the process. GC is still not guaranteed as the interview process could be harsh. Lastly you will always have that fear of doing something wrong. To top it off, it is ILLEGAL!!

If GC is your priority, maybe you should look for a job that has a more stable route to GC. Your avenues aren't closed yet; don't do anything stupid.