Split CV Boot Repair. Does it ACTUALLY work?

Do these easy, quick split-boot repair kits ACTUALLY work? I previously did a split CV boot repair on the driver's side front axle when I discovered it leaking. I spent quite a while getting the repair to work. I know the I had gotten the glue on perfect when I did it the first time. Well long story short, you'll just have to see or skip to the end for the conclusion.

COAST Headlamp: https://amzn.to/3ESX0iJ