Laundromats exist everywhere! Most folks in other countries don't have personal washers and dryers, so all you need to do is know the word for Linsey in whatever language is needed. We've done laundry in lots of countries, and cheaply, too. ...
OK, I'm not all that experienced at travel (mostly short business trips), but when I went to Budapest with a friend (who is very experienced traveler, and for long stays), we simply could not find a 'laundromat'.
We figured, no problem, looked around, went through tour guides, couldn't find anything, asked at some business place and got directed to someplace that just gave us blank stares after they found someone who spoke English (and this is right in the city), no luck!
When we asked at the hotel, we got the look again "You don't have wash machines in your homes in the US?". Yes, but we aren't home. And we do have laundromats at home for people w/o. All we could find was "dry cleaners" kind of places, and we could buy new clothes for the prices they charged (and this is in a country where most everything was very inexpensive). The hotel rates for laundering were also high enough to justify buying new.
We ended up buying detergent there and washing stuff in the bathtub or sink ourselves, and hanging it in the room to dry. Not all that much effort, but rinsing is a pain, and not what we wanted to do on vacation.
Maybe things are different in other places, or maybe we just never caught on to how to find a US-style 'laundromat', but that's how it was for us.
I probably could not even manage to pronounce 'Linsey' in Magyar (their name for the Hungarian language). I can't even pronounce 'Magyar' ('Mud-yoor'?).
https://en.wikipedia.org/wiki/File:Hu-magyar_nyelv.ogg
-ERD50