Yes-It does dry out my skin, but no more than your typical benzol-peroxide cleanser. To remedy the dryness, I find that applying the clear aloe-vera gel right after washing eliminates the dryness.
I'm havn't heard about the selenium issue, although I'll look into it, now that you mentioned it.
I also found that applying vitamin K gel (available at CVS) is working well to reduce redness, and accelerate healing. It also helps with dryness from head and shoulders.
With all this flury about what cleanser to use, I'm surprised more people havn't heard of the head and shoulders treatment. I noticed results in about a week.