Is there a self-serve laundry in/near Bairro Alto and Chiado? Alternatively is there one in/hear Baixa and Avenida?
Self-service laundries are very rare in Portugal. The "5aSec Lavandaria" has same day wash & dry service for about €8. Just drop your clothes off in the morning and they will be ready later that day. It's located near the Baixa-Chiado Metro stop at Rua do Crucifixo 99, open Mon-Fri 8:00-20:00, Sat-Sun 10:00-20:00.