I will take a look at the duplicolor. I don't think a silicone spray will work. The old coating is peelng off. Looks like some sort of plastic or vinyl. Kind of reminds me of thick dead skin.
Why risk the chance of losing a fish due to the fish breaking through old webbing? Buy a new one and keep the net out of the sun in the cockpit when the boat is docked.
The duplicolor is a great product! If you look in the automotive department it should be there. I used the rubberized undercoating for trucks and it worked great! Just hang the net so it hangs like a basketball hoop and put several layers on it.
Outdoor Hub mobile, the outdoor information engine