The only business activity available is to do laundry, but sims won't wait for them or try to dry them. They will literally put clothing in the washing machine and leave the business a few moments la...
Ideas
It's kind of silly some of the things they included in the pack that they had to have known wouldn't work. I've only ever seen sims with the neat trait autonomously press the button to wash or dry clothes, and even with the trait they barely ever do it. I've never seen a sim without the neat trait autonomously even try to do laundry.
There's just no way a laundry mat would work on its own. You'd need to offer another activity for sims to stick around and then have a sim that you controlled constantly doing laundry to keep the machines clear.
Edit: Noticed that I spelled laundromat "Laundry mat." I didn't change it because that's funny.