Introduced in 1949, Joy was the first liquid synthetic detergent. It is still considered the best for lathering and rinsing in cold salt water. Comes in Ultra (concentrated) and non-Ultra varieties.
Several models of water bags you hang above you for a shower. Can be used on deck, or above the head's deck hatch.
Concentrated soap that works in salt and fresh water. For hair, body, clothes, dishes. Biodegradable.
Made to lather in sea water and rinse off clean. Three types with different oils.
This extensive and authoritative dictionary of cruising terms defines Soap as Joy Liquid and Dawn Liquid. "Dawn and Joy contain ethyl alcohol, which I think is the reason they work in salt water."