Hour glass baby blanket

I just finished my first baby blanket and it looks like an hour glass. The middle is tighter than the ribbing. I know it probably needs to be blocked, but I need someone to walk me through the handwashing process (kind of soap and how to block) :??

Here is a really good article on blocking:
http://knitty.com/ISSUEwinter02/FEATdiyknitter.html