The following is a edited version of a piece that appeared in my "Ask RSD" column in the Oct '99 of "Rodale's Scuba Diving:"
"How do I clean a smelly wetsuit?
This periodic task contributes much to the comfort of the diver and his companions. There are a number of ways of accomplishing this, but none should be attempted until insuring that they are consistent with the manufacturers cleaning instructions.
As well as regular cleaning/deodorizing, some preventative measures will help keep odors down. These include limiting the warming of your suit, removal after each dive to avoid perspiration, and rinsing it well in warm water and hanging it to dry after each day of diving.
Cleaning/deodorizing methods include: (1) Washing in Woolite, Odor Be Gone, or Sink The Stink, the latter two being available through many dive shops. The suit should be soaked in one of these for at least several hours and preferably overnight. While not necessary, you can then either agitate by hand or place in a front loading washing machine with at least a gentle and preferably a hand wash setting. A top loader set at normal could rip stitching, especially in suits made of neoprene or similar substances. Alternately, the suit can be lathered by hand using baby shampoo, followed by thorough rinsing; (2) For heavy odor, a small amount of liquid fabric softener or vinegar can be added to the rinse; (3) After the suit is clean but still moist, mist it completely with Febreeze, available at many grocery stores (this one really helps); and (4) Dry the suit by hanging it outside until dry, avoiding direct sunlight. If you have a drying space in your basement or the like, simply hang it there. The suit should be placed on a wide shouldered hanger and stored in a place which is cool, out of direct sunlight and well ventilated."
Best regards.
DocVikingo
PS: There is no advantage to washing a new wetsuit before wearing, and Woolite will serve just fine.