As you scour the Commonwealth you'll discover discarded clothes. Some of the items you find will be dirty, which makes sense given what's happened in and around Boston. Thing is, there's no way to wash these dirty clothes.
While there are stores open for business in the Commonwealth, there aren't any laundromats. So you'll need to take matters into your own hands.
Laundromat is a basic mod for both PS4 and Xbox One that allows you to wash dirty clothes. The mod actually adds two functions to the Chemistry Bench. One allows you to wash dirty clothes and the other allows you to dirty clean clothes using some dirty water.
The feature is unlocked from the get-go meaning you don't need to perform any quests or acquire any perks to start using it.