He decides on a small test.

Shortly before reaching his home, he paused and took the Sex Note back out. "...if this thing is for real... How powerful is it?" He decided to try it out, and was about to write something, before realizing a small issue... "Wait... I don't have a pe-"

Clatter! He paused, and turned to see a pen rolling on the street. "...okay, now I KNOW something is up," he remarked, reaching down to pick it up. He still saw no one around though, so he ducked into an alleyway. If this was just some stupid joke, he didn't want them reading what he wrote, even as a test. But what did he want to do to test this thing?

He decided to try it out on Hestia after a moment. If it could affect a goddess, even one who exists on this plane, then it should affect just about anyone. So, after taking one last look around, he opened the Note up and started writing, "Hestia will greet Bell Cranel in the nude when he returns home. This nudity will not concern her, in fact, she will openly flaunt her body for Bell."

His nose bled a bit as he imagined Hestia naked, and set the Note back in his bag. If this didn't work, he could always try again with someone who wasn't a god... assuming the Sex Note really was some kind of magic item, and not just a prank, or just someone's means of writing down sexual fantasies to fap to... Only one way to find out for sure though.

He exited the alley, and before long, his home came into view. He entered, his heart beating a little faster than usual in anticipation, but not expecting too much. "I'm back!" he called.