wash (something) up        
phrasal verb with wash verb uk/wɒʃ/ us/wɑːʃ/
A2 UK清洗,洗刷(用过的餐具) 
to clean the plates, pans, and other things that you have used for cooking and eating
  He washed up his mug and put it back on the shelf. 他洗干净自己的杯子并把它放回架子上。 
 - More examples
 - I just need to wash up these dishes.
 - I washed up all the plates.