Sorry to hear about your vision issues. I just had cataract surgery six months ago. I am using a calibrated 27" 4K monitor.

Since neither of us has perfect vision, I used PS Elements to measure the changes at the pixel level. I searched the lizard image for something close to middle gray. I found a spot at pixel x=761, y=528:
Plus or minus three units on a scale of 0-255 is a barely perceptible change in color. But the change in brightness in the overall image is noticeable as is the apparent change in saturation and contrast. We can leave it to others with better vision than ours to judge whether Bob's method improved or degraded the image.

Nevertheless, the changes really amount to tweaking the image to achieve the result the photographer desires rather than actually correcting the image to more closely resemble the "actual" colors.

But an ounce of prevention is better than a pound of cure. Starting off with a daylight white balance is still easier to work with than rolling the dice with Auto WB and needing to correct a color cast that the camera might inadvertently introduce in the JPEG or "suggest" to the raw converter.

To which image or images are you referring?

If you are speaking of this one, there was some degree of improvement. But another poster applied the method after masking out part of the image and got a different result.

If you mean this one, the image was degraded and a purple cast was introduced.

In this case the method was applied and it removed some of the yellow cast.

In this case the post mentions that it does almost nothing for a gray and overcast day. Of course, it might have if the original captured image had had a serious white balance issue.

I already pointed to my images where the method failed and explained why. I also posted a couple of additional images where the use of the method would have ruined the color.

Even the two images that Bob provided here and here, fully processed by him, showed no appreciable change in color cast.

Bob's a nice guy and we all like him. But that should not cloud our judgement

Are you serious? Of course it looked different! Bob had the camera set to UniWB. All of his JPEGs are green because of that.

When he removed the UniWB setting the image reverted to a default WB, probably Daylight. Removing the UniWB setting has nothing to do with his methodology.

Did you seriously think that removing the green UniWB color cast had any relevance? No wonder you are confused!

The color cast adjustment was used between the images labeled "Initial WB but No Color Cast Correction" and the one labeled "Color Cast Corrected". Compare those two images.