The absorption of SN happens in the small intestine. If you eat with it (or shortly before) the SN will be stuck in the stomach with the food. The body will have plenty of time to recognize the poison and you will likely vomit everything (which will be messy because of the food).
Food spends up to 4 hours in the stomach and up to 6 in the small intestine. So it would take 10 hours for everything to be empty. Of course, that depends on the type and the size of your last meal.
I know that being hungry for so long is unpleasant and having to wait for 10 hours is nerve wracking but it's to minimize the unpleasantry of the process.
I am currently struggling with taking the SN myself. I have everything ready to go but I'm still scared of what it's going to be like.
