Well I was motivated one evening to try this so dug out my t-shirt, plastic lemon from the fridge and the Morton's salt. After two applications of the salt and lemon the stain was significantly lighter and if the spot hadn't be right in the middle of my chest I probably would have worn the shirt as it was. So today I thought I would give it one more shot and follow all the instructions and lay the shirt in the sun. And wouldn't you know it (or maybe not since this was news to me) after about an hour or so in the sun the lemon/salt patch was dry and the spot was completely gone!
I am laundering the shirt as I type this, but when I checked it before putting the load in the dryer the stain had in fact been removed. I am simply amazed. I wish I had all the clothes I have thrown away over the years back. I wish I would have taken before and after photos, but I think I have another shirt to try it on.
• UPDATE •
I just treated another shirt and I took photos this time.