ok first you train it to jump. Then you train it to aim for things. then you tell it to aim for the cooler below the tank and waa laa. No net needed. It only takes 6 years for the whole process so if you start now that tank will be moved in no time.
Go with expensive hobby's bag idea. I use it on my fish as well and I have some close to 30". Works without issue. Just be careful of the catfish barbels. They hurt a little. lol
I would recommend against the "death grip" strategy, however you can do what i do when I move large fish(10"-24"). Get a large clear bag(fishbag) and lower the water level of the tank, and slowly and calmly dip the bag in the tank and gently persuede the fish into the bag and lift up twist and tie. I moved many large fish including but not limited to a 20" silver arowana, a 16" red belly pacu, and a 24" royal clown knife. Went well with all of them