Left hand stroke therapy

Getting something into my left hand is an interesting exercise in patience. While my hand is not curled into a fist the fingers are not hanging loose. Anything larger than a bottle of soda is impossible to grasp. The top also needs to be sealed, an unopened can or bottle is only possible because I need to be able to tilt it on its side prior to forcing my fingers open. Open glasses will not work because I can't hold it upright and pry my left hand fingers open at the same time. Soft sided styrofoam or cardboard cups are also out. My basic therapy for this is passively flexing my fingers open and closed with my right hand. I used to have a plastic hand splint for nighttime use to keep my fingers straight and splayed but after three years of continous use the plastic rotted.