This American self-service launderette offers with high quality washing machines and tumble dryers (still a rare sight in PL), giving you the chance to finally clean up the contents of that rucksack. Everything is in English, the machines take cards and cash, there's free wi-fi, and washing and drying only takes 90mins total. Really, this is as easy as it gets. Also in Gdańsk in Galeria Handlowa Madison.