The dryer is safe to use as is. Alcohol evaporates upon contact with air, so no traces of the chemical qualities nor the flammable characteristics of it remain. The blue discoloration is fairly normal and occurs in many dryers where no alcohol was introduced. Certain cleaning products can cause the enamel in the drum to turn blue, but it will not harm humans in any way, nor is it likely to rub off on the load. I see blue drums like this on many of my service calls.
Unless the dryer needs additional servicing, such as JW suggested, there is no need to disassemble it. If blue is not your color, you can refinish the inside of the drum with any hi-temp enamel available at auto parts stores.