My GSD is a spoilt brat. Apart from one blue ball, he loses interest in new toys with 2 minutes of receiving them. He literally has hundreds of toys that he never plays with even if we do the rotation thing (the ultimate plan is to donate them/give them away but it's a big task). It took us all a while to fight the urge to buy toys for him that we came across.
We often give him cheap(er) non-toys to destroy. E.g a "plastic-y" bag from Primark with his favourite ball hidden inside. We might hide the bag and get him to find it. Does anyone else do this? I think it works as he knows he's only allowed to chew things we've allocated him.
He is supervised and we make sure to avoid choking hazards.