There is not set way. It all depends on "what works for you" if you can go back to bed and an hr later or so you start having eliminations for the next hour or so then it works for you if not then it's not for you. There are other factors involved besides whether you go to bed or not, bottom line is hydration hydration hydration. You need to drink at least equal amounts of water to the lemonade or half your body weight in oz. Dehydration in the most common reason for the SWF not to work. If by an hr after the SWF I haven't had any aliminations then I will drink a whole quart of water.
There are also some exercises by an Ayurvedic doctor in the FAQs that you can do to help the SWF do it's thing