laundromats in Croatia and Slovenia

Dubrovnik only had one laundromat as of last summer--it's just across the street from the Hotel Bellevue in the Lapad section of town. (We didn't use it and just washed out a few things in our room, so I can't vouch for it personally.)

Based on my travels in this area I would not expect to find a laundromat.

We always rinse laundry in our room. Take a short line with clothespins and wash as often a needed. As you go, look for a laundromat; when you find one take advantage of it, but dont count on finding one anywhere in Europe.