It taken enough, the body will be in a state of diarrhea and get rid of excess water within minutes, thus curing the condition. A reasonable dose for me in such dire emergencies is if 5 liter water is drank is 1/4 x 5 = 5 1/4 teaspoon of sea salt and about 2 teaspoon of baking soda. It looks like a lot, but did you forget, you were drinking that much water, something has to neutralize that dangerous amount! Of course this is based on ball park figures in case of water intoxication. The amounts are never exact and more experiments are needed however. If I have sometime in the future I can do the maths to be more exacting.
Eating home made fresh goose berries jam or pickle can help increase blood platelet count. To make Indian gooseberry jam, wash approx 1 kg of Indian goose berries and prick them with a form. Now boil them for two to three minutes in 2-3 liter of water. Let it soak in water for next 24 hours. Add 1 kg of brown sugar to the mixture and let it soak for another day. Next day add some citric acid, approx 3 gm, and boil it on medium heat for 10 minutes. Store the jam in a jar for another 48 hours. Your home made Indian goose berry jam is ready to use. Eat 3-4 goose berries, empty stomach, every morning to increase platelet count.