Do you remember seeing the pink or blue shoe going around the internet? I got really into trying to understand this one and tried doing this practice to switch sides of my brain. I didn't give it more than a few minutes, which was not enough to change the hemispheres, apparently. Then I took a nap, while noticing which nostril was dominant before I slept. When I woke up, the other side was dominant and it switched what I actually saw from blue to pink. Here is the link. It is a great test to actually be able to have a visual confirmation. :-)
https://www.insider.com/what-color-are-the-shoes-pink-white-teal-gray-2017-10