I havent heard of gel wrap that goes on the hoods.
You could certainly fashion up something, the world of cycling is full of hacks. Someone on this forum commutes thousands of miles each year and uses pool noodles for handlebar cushion so anything is possible.
The suggestion of adding electrical tape over gel pads atop the hoods seems like the best solution if you are not interested in getting a different bike/riding position. An upright riding position would take pressure off your hands...