I just got back from a trip to the Philippines last week. I took and also entered bills while in the Philippines. I hope to get some international hits from the bills I used while in the Philippines.
I exchanged the bills for pesos at several places around Quezon City. The only problem I had with exchanging my marked Where's George bills was at the SM mall in Baguio City. In Quezon City, The only problem I had was with a non-Where's George bill. In fact, they took my Where's George bills and handed the other marked bill back.
The biggest problem with Georging in the Philippines is that they have a clean money laws were it is illegal to mark on the Filipino Peso. Some Money Exchanges use the policy on all money. I found that if one will not get the bill another one will.