Well, It is risky just for one or two sites.. and applying that takes like 4 min time, so why the hell not?
Might be worth trying or do just for fun. The thing is, it is not _illegal_ and google ban will not affect your all sites. G does not know all your stuff.
And what comes to black hat... In my experience, all the IM big timers have used some black hat to get there.... Or they're lying. Nothing against BH here. There's a big gap between black hat and being unethical or doing something illegal.