I don't think anyone outside the Philippines still take him seriously. As for the containers unless he can find a connection between that private company and the Canadian government, he really can't force Canada to do something about it. The Philippines just don't have leverage in anything.
He can claim a connection of course (like how almost everyone believe the CCP give orders to Chinese companies operating outside China) but he need to find a way to sue them.
I don't remember if they've already went after the local company that's supposed to "buy" the "recyclable" materials.
everybody can paint or buy shipping containers and put a flag of another country on it. its easy to blame foreigners, the pazific has many big countries that might put waste into it, duterte simply blames the richest & weakest at the same time. wouldnt be easy to blame russia, china, japan, usa and others are poor as this