Boil 2 cups (475 milliliters) of water with 3 tablespoons (26 grams) of washing soda. Remove the water from heat, add the leaves, and let them soak for 20 to 30 minutes. Once they are done soaking, scrape the pulp off like your normally would.  This process is similar to the method above, except that you are not cooking the leaves continuously. This method is ideal for small batches or delicate leaves. This will take about 2 to 3 weeks; you will also need to change the water every few days to keep it from going rancid. You can add some bleach to further prevent decay. Once the leaves are soaked, scrape the pulp off using a soft toothbrush. If you are adding bleach, plan on using a 1:30 bleach-to-water ratio. Combine 2 cups (475 milliliters) of water with 4 ounces (113 grams) of a biological detergent. Add the leaves, then boil everything for 30 minutes. Rinse the leaves off, then scrape them clean with a soft toothbrush. Press the leaves between two sheets of blotting paper for 2 weeks.

How would you rephrase that briefly using Vietnamese?
Ngâm lá trong nước thay vì đun liu riu. Ngâm lá trong nước trắng nếu bạn đủ kiên nhẫn. Thử dùng bột giặt sinh học.