You can also use that tendency to make them self-destruct.

Any time you're given a number for the save, just say "huh." Like it was an interesting result.

I do get the meme, but I can't really think of a way to hide specifically the result of a failed wisdom save from a player.

Like how would you tell a player sometime like "You feel like Alric is a wonderful person despite the corpse he is looming over" without it being very obviously a failed save against charm person? Same for basically any other enchantment.

Other spells with wisdom save are even more obvious by virtue of taking damage, or being turned into a cow.

Detect thoughts and dream are the only two I could find where rolling in secret works for wisdom saves.