Laundry

What city?

Ask at your hotel (that's what we always do) but it looks like Norge Exquisit on Paris-Lodron-Strasse 16 is the closest. Use a translation tool for English.

https://norgeexquisit.at

(I assume you're staying in Salzburg?)

Rick mentions some options in his book

If you want a self-service laundromat and not a dry cleaner, try this place - https://waschsalon-salzburg.at/. The website can be switched to English from the menu.

I've used the Norge that Kathy mentions several times . Reasonably priced same day service wash . Dropoff in the morning , pickup about 4 PM . Saves the time sitting in the laundromat . ( although I've done alot of that as well ) .

I don't know know which city that hotel is in. Austria has several large cities.

I was very successful getting laundry done in Seefeld in Tirol but there's no Sheraton there.

I'd assumed the OP is staying in Salzburg due to a previous question about that city, and mention in that post that they were staying at the Sheraton Grand. Bob?

The Norge Exquisit website I'd linked does advertise self-serve laundromat service (Waschsalon: Selber Waschen).

Translated:
Laundromat Salzburg
You don't have a washing machine at home or would like to wash particularly large clothes? Our laundromat at our location at Paris-Lodron-Straße 16 offers you a cheap way to wash and dry your clothes and textiles comfortably.

Yep, it's a personal preference how to manage a wash-up. We just prefer to do it ourselves so we can control water temp, sorting and folding. Honestly, it really doesn't take us long, and we can chat about our sightseeing adventure while the clothes tumble. :O)

Thanks for tips everyone! We did both: washed out in sink, hung to dry in bathroom and sent just a couple of things that needed a dryer out via hotel. Decided time it would take to locate and walk to laundry would be better spent walking to old town.

FYI , The Norge , whether you choose a service wash or waschsalon option , is right on the way to the old town

Use Google Maps and do a search for Waschsalons. Eco-Express is a chain to look for. I find them clean and easy to use. Be sure to check opening times and days. I build time into my schedule each week so that I can travel light. Most open early and I can do laundry before museums open at 9:00 or 10:00.