Peep sights are mainly an anchor reference, which is exactly what a kisser button does for you. If you want to try it without a peep, then I'd have to say you probably should use a kisser to keep your anchor consistent, which will keep your long range accuracy from going to pot. Kisser to your lip, tip of your nose on the string and align one edge of the string or the other with the side of your pin. Doesn't matter which edge you use as long as you're consistent with it.

The shooters in the Olympics were getting pretty decent long range accuracy using that method.