Those cat scratchers are awesome!
Niven also has a dig box. Hers is full of hay, paper, and bits of her old toys. Periodically I sprinkle some forage mix in there. She loves hunting for the tastiest bits.
Sticks, especially apple wood. She has a cardboard tray I keep stocked with various sticks for her to choose from.
Balls: willow, palm, or sea grass. Loves destroying those. Or just dunking them in her water dish.
Hay treats. We get both the oxbow lollipops and the dumbbells. They are great for when we are going to be gone longer than usual or when we need a distraction to keep her out from underfoot.
Any toy that can be filled with a few treats or pellets are also a big hit (stacking cups etc).