Well, I think that a lot of people mask the sides to protect them from the stain. Personally, I tried it, and found that it's worse to mask it, as the stain can somehow seep through the edge?
What I did on this one (and it came out perfect) was to rub the stain with a cloth, and be careful not to touch the sides. Sounds risky, but it's actually quite difficult to stain the sides this way.
I know what you are thinking, and the answer is yes. Yes I did make a burst by hand. that was the tough part.