Unless Immigration has orders from their central office to blacklist, the decision would be up to the local office chosen for self turn-in.

Therefore, get some information on how liberal or conservative each location might be, and choose the most liberal city in which to have your friend turn himself in, to avoid adverse effects.

Hopefully, they'll just let him leave peacefully. It would save them a lot of trouble too.

You should definitely have him start by looking over the information at USCIS.gov. Then, he should consider asking an attorney. The reason i say that, is that by turning himself in he may well risk being placed in a detention center, essentially jail. In addition, if he is deported it is not likely they will be quick to let him back in.

The Philippines is getting strict about overstayers. Since last year they are requiring an acr icard for extended visa holders and will not allow you to board a plane without paying the overstaying penalty or exit clearance. Previously, you were able to pay off, "bribe" the officals at the NAIA airport, but it is getting more difficult to do. You friend should stop by the U.S. Embassy on Roxas Blvd. and speak to someone there about their situation. It is possible that he will be allowed to be deported without staying in jail.

As far as turning himself in to the Philippine Immigration, I actually doubt they would even know what to do, and they would likely tell you to go home. I have never heard of the local philippine immigration rounding people up unless they are wanted in their home country.