⁌ ULY ⁍added a comment 5 лет назадWASH UP - is much more natural and current: https://books.google.com/ngrams/graph?content=have+a+wash%2C+wash+up&year_start=1800&year_end=2008&corpus=15&smoothing=3&share=&direct_url=t1%3B%2Chave%20a%20wash%3B%2Cc0%3B.t1%3B%2Cwash%20up%3B%2Cc0