Grate the laundry soap, add a glass of salt and 1 tbsp. l. starch and citric acid. Add a little water to the mixture to make a paste.
The material advised applying this paste to the stains and leaving for at least 10 hours. After this, you need to wash things thoroughly.
The site also emphasized: if your clothes fade during washing, immerse them in water with ice and a glass of salt as quickly as possible. Wait until the stains are removed and continue with normal washing.
