The Woshu Woshu no Mi is a Paramecia-type Devil Fruit that allows the user to literally "wash and hang out to dry" people and objects as if they were clothes, making the user a Laundry Human (洗濯人間,Sentaku Ningen?). It was eaten by Tsuru.
"Woshu" is short for "wosshu", the Japanese way to pronounce the English word "wash".
In the Viz Manga and FUNimation subs, it is called the Wash-Wash Fruit.
Strengths and Weaknesses
The main strength of this Devil Fruit is that it allows Tsuru to "wash and hang out to dry" people and objects as if they were clothes. This seems to render her victims unable to fight back or move. According to Oda, "villains who have been dried get their hearts a little bit cleaner as well; their evil hearts become fainter, so that's a dangerous ability against pirates".
This power has no known weaknesses aside from the standard Devil Fruit weaknesses.
Tsuru has so far been seen disabling pirates with this power. She can also "clean" a limited amount of evil out of her opponents' hearts, rendering them slightly less evil. It is unknown how she activates her powers.
This Devil Fruit is very similar to the Awa Awa no Mi, as both fruits possess washing and cleaning properties.