for my suits I use a wetsuit cleaner/conditioner by O'neil.
But if you need a quickfix soak it in a tub with warm water and a little dish soap. Let it soak for a while then rinse it, dry it, should be good to go.
"Out there in the surf is where it's at, that's where the line gets drawn in the sand between those who talk fishing and those who live it."
- a wise man.