Shave 1 pound of laundry detergent soap into a 5-gallon bucket using a cheese grater.
Pour 3 gallons of hot water into the bucket and stir the mixture with a wooden spoon until all of the soap shavings have dissolved into the water.
Put on latex cleaning gloves and place the fabric you wish to become water-repellent into the bucket.
Hang the fabric over a shower rod to dry for 30 minutes once it has been thoroughly soaked in the mixture.
Dip the fabric into the detergent/water mixture a second time and allow it to dry completely.
Pour 4 ounces soya bean oil into the second bucket.
Slowly add in 2 ounces turpentine. Gently stir the turpentine into the oil while pouring to ensure that the ingredients are properly combined.
Pour the turpentine and oil solution into a spray bottle and spray a coat of the mixture over the now-dry fabric.
Allow the first coating of turpentine and oil to dry for 15 minutes before spraying an additional coat. Allow the material to dry completely before using it.