He sounds very tactile. Could you offer him more activities that involve hands on and exploring the senses. I know you asked for ideas to get him to play with his toys, but you could try things like play dough or clay; a bowl full of rice to dig and run his fingers through; maybe a sink full of bubbles: or some cooked spaghetti noodles. That way he could really explore but you could set it up in a way that is easier to clean up. Maybe if he knows this type of play is available he could learn to ask you for it instead of digging in the fridge.