Guilty verdicts from war crime trials would accomplish the same thing.
It would establish a precedent and if Obama were to get a GOP predecessor, he would be pardoning Obama for Benghazi, Obamacare (they'd figure out how), Illegal wars not issued by Congress, etc. Every subsequent administration would be doing it and it would completely water down the act. It's a pretty passive aggressive thing to do. I actually think it sounds incredibly childish.
This ordeal makes me furious to this fucking day. There's no win. The options are: A.) This passive aggressive political bullshit that means nothing. B.) Do absolutely nothing C.) Actually hold the criminals accountable for their crimes. A is crap and would do exactly what you say, and remove the reality of what happened after time. It's another disconnected, political move separate from reality to people then. C is the most laughable thing on earth, because we know criminals aren't convicted in this country when they any morsel of power, let alone what they people have. So we're left with B. We do nothing, shit keeps happening just the same, and the government goes unchecked again, the people are more jaded and hateful, and nothing changes for good.