Nobody knows exactly how big this oil spill is, but one thing is certain: BP's public relations effort has been disastrous. Even the PR guy for Xe Services, the mercenary company formerly known as Blackwater, thinks BP has bungled it.

Today, President Obama called out BP for its efforts to divert blame in recent days: "You had executives of BP and Transocean and Halliburton falling over each other to point the finger of blame at somebody else... the American people cannot have been impressed with that display, and I certainly wasn't." And this was before we learned of the supremely boneheaded quote BP CEO Tony Hayward gave the Guardian today:

The Gulf of Mexico is a very big ocean. The amount of volume of oil and dispersant we are putting into it is tiny in relation to the total water volume

It's almost as if Hayward is trying to make us feel OK about hating BP, which is considerate, but not really the best PR strategy. In fact, BP's image is so damaged at this point, more than three weeks into the catastrophe, that it's hard to think of a company that's been so universally reviled in the past. Actually, it's not. There's Blackwater. The private military company was so despised for its conduct in Iraq—which included killing Iraqi civilians then bribing people to be quiet about it—that it had to change its name to Xe Services.

So we called up Xe's spokesman, Mark Corallo, and asked him if he had any advice for BP. Corallo, who runs the Washington PR firm Corallo Comstock Inc, represented Blackwater in the mid-2000s, quit, and was rehired to represent Xe Services. Since then, he's been busy with the weapons trial of five ex-Blackwater officials and Xe's bid for a $1 billion Afghan police training contract. (Corallo has also represented beloved public figure Karl Rove.)

First of all, Corallo says, BP needs to realize there is no way they can possibly emerge from this looking good. "In a situation like this, there is no good answer."

The key to minimizing the damage is to take responsibility early and often.

"There are times when you have to man up and take your lumps, and this seems to be one of those times," Corallo said. "There have been several times when I've counseled clients to just flat-out take responsibility... you have to come out and say 'this is our problem. this is something that we're dealing with immediately and we'll take steps to make sure this never happens again.'" Of course, BP's first public relations gambit was blaming Transocean, the company they leased the oil rig from. "Nobody's buying that. It shows that you're living in this bunker mentality."

Also, don't say that the immeasurable environmental, personal and economic catastrophe you've created is "tiny," no matter how besieged you feel by the media and the public. "Don't go and sell that one," Corallo said. "You're already on a life raft with one paddle. This is like saying 'Hey let's throw the other oar into the water and make sure we throw chum to the sharks so they come and get us.'"

Ultimately, though, Corallo thinks the BP brand will survive without a Blackwater-like makeover.

BP is an established brand. The brand can come back. The brand can survive this. The way you do this is committing to a long-term campaign that acknowledges the problem, and addresses the problem with good works. You've got to have a sustained campaign to 'make it up.'

Thank God!

[Photo of a BP protest, left, and a Blackwater protest, right, via Getty Images.]