If you managed to hide a body in the excavated soil between the driven piles but before concreting works begin, chances are the body will never be found - like EVER. Sure the structure might get haunted after that, but it's not like the ghost can say or write "Yo! I was murdered here by yours truly!"
Making a batch of Bunuh Seliseh vinyl stickers and putting them up in an area he's never going to visit. Someday he'll be watching television, and there'll be a random American wearing a T-shirt that says Bunuh Seliseh. Turns out there's several pages of merchandise on Etsy, and a hot new mobile game. And the cartoon guy in the mobile game looks an awful lot like him.