Does SN have an expiry date? Which SN is better to use, the food grade one or the technic one? How to not throw it up without taking antiemetics?
As summary:
Food grade 99% is better, recommended dose is 25g, there is high risk of throwing without antimetics, and said this.. probably the described antiemetics schedule is quite excessive, as medicine/anatomy student i have no idea from where that scheduling come from, probably a couple of pills 1.5 hours before SN, would do the job just fine, metoclopramide is a gold choice as antiemetic, i personally suggest adding also a couple of loperamide pills in the afternoon, as long the antiemetic may have some laxative side effect. Fasting half day before the process is recommended.
The medical journal db reports no interactions between loperamide and metoclopramide, so they are fine togheter.
All the recomendations of the main SN guide are just a "fine tune" for the process.
Talking about "expiration" for SN is not exacly appropriate, because it concepts as preservative, differently from medications, i would say that if not exposed to oxygen, would keep it's properties stable for at least 5 years, after that it may lose some potency and part of it may became nitrate, that even if still poisonous would not act as oxygen withdrawal from blood.