It's only just a propaganda to win an election. You would hear that same kind of promises from the politicians over and over again. Almost all past presidents made the promise that the country will have a better economy if you voted them but look the Philippines is still a poor country.
Pres. Duterte should clean the Customs first because this is where the majority of shipment of drugs from other countries came from. It's a common knowledge the Customs is the most corrupt agency in the Philippines and this is one of the reasons why drugs can easily be ship to the country
Its a common knowledge that in the world of politics that all branches of it is corrupt.