My fifth graders think apostrophes are just decorative sprinkles for words

I swear I've taught possessive apostrophes six different ways, but my students are still writing things like "the dog's ran" and "the girl's were playing." One student actually told me "apostrophes just make writing fancier" when I asked why he put one in "book's" (as in multiple books).... I've done direct instruction, games, editing practice, even a ridiculous song about apostrophes that I made up. Nothing sticks! I'm considering having them physically act out contractions by standing together, then having one student duck down where the missing letter would be 😬 but I'm afraid they'll just think I've lost my mind. Anyone have an apostrophe breakthrough activity that finally made it click for your students?...