I have some brown marks on my penis, later found out to be caused from rigirious rubbing. To try and remove these marks I tried many ways to get them off but I found one very quick and painless way of doing it:
1. Set up the latex glove ( the white stretchy ones are best ).
Take a latex glove and tie a knot around the fingers. Also knot the wrist area so it fits tight around the base of your penis.
2. Fill the glove with shampoo/lotion
Fill this glove with a shampoo lotion coktail of sorts, some work better than others, I found Prell to be the best.
3. Apply glove over penis
let it soak on there for around 3-7 hours. Make sure it is air tight.
After a day or two your skin will get very very smooth and shiny. Then it will begin to dry and eventually resemble a catchers mit. Shortly after that the top layer (or two) of skin will begin to dry and flake off. Fresh skin will be there. Some cracking and scabbing may occur if you get many errections at the time of extreme driness, but no scares or other marks are left.
This removed a lot of my brown spots, If I do it a few more times I think I will remove them all, some are deeper into other layers of skin.
Hope this helps you guys, I have been very self concious about these, but think I am going to get rid of them with this method.