How to use DaVinci Resolve to blur sensitive info in videos without unwanted blur windows (Ver 17.0)

Casey Faris' video    • How To Blur ANYTHING in DaVinci Resolve 17...   was helpful to learn about using DaVinci Resolve to blur sensitive information. However, he uses keyframes to remove the blur window after it's not needed. I found it's not easy to make it work. Instead, splitting the video seems a simpler solution. Note in the example the tracking part is not really necessary because the "object" is not moving, but it is needed if it is moving.