If it ain't broke don't fix it
If you can't fix it don't break it.
For an experiment, the next time your hands are oily/grimy try using a little engine oil (maybe Shell Rotella T) as though it were soap - rub it in. You will be amazed a how it dissolves the grime. It still needs to be removed with soap but this demonstrates (at least to me) how well the detergent works. I would not bother with anything beyond maybe lowering the interval between oil and filter changes, or what I did when I first bought my boat, a double oil change. (I also did a double coolant change)
I figure oil additives are like vitamins, the biggest benefit is to those who sell them to you.
By the way, when Woodster referred to changing to no oil I wonder if he was making a sarcastic reference to the advertising video that purported to show that after a certain oil had been used the engine could run with no oil.