From the Hinton link: "Letters submitted to mathematical journals of the time indicate more than one person achieved a disastrous success and found the process

From the Hinton link: "Letters submitted to mathematical journals of the time indicate more than one person achieved a disastrous success and found the process of visualising the fourth dimension profoundly disturbing or dangerously addictive." I wonder whether anyone in modern times has tried it, and how it turned out.