DIY Homemade Laundry Detergent Recipe- Laundry soap Castile recipe ,So if you choose a scented bar soap make sure it adds to or blends well with the essential oil you choose. Most bar soaps will work however, go for Ivory soap, castile soap, or something similar for the best results. I chose to use an unscented bar soap so that way the essential oil scent was the primary scent of the laundry detergent recipe.DIY Homemade Laundry Detergent RecipeSo if you choose a scented bar soap make sure it adds to or blends well with the essential oil you choose. Most bar soaps will work however, go for Ivory soap, castile soap, or something similar for the best results. I chose to use an unscented bar soap so that way the essential oil scent was the primary scent of the laundry detergent recipe.