You know your body better than others. Do you tend to regurgitate when you consume something "bad"?
If it's a concern of yours and you have excess SN, I'd mix as many doses as you can with the SN that you have. Best case you don't need them, worst case you have them available if necessary.
This would be different than regurgitating something bad. This would be the body's survival response, formed over thousands of years, to rid the body of poison that it "knows" will harm it. I think it's different than consuming some bad milk or something, then vomiting that up, that would only make the body sick.
Without an anti-emetic, I doubt you could have enough glasses prepared. I'd have at least 4 glasses made up, maybe more. This may be more difficult to do than you realize. When you throw-up the first glass, you'll have all that nasty taste of SN and stomach acid in your throat and mouth, and you're going to have to drink another glass right away. That may be harder than you think. Then, you may throw-up the second glass fairly soon after drinking it, and will have to drink another glass right away, too, still tasting all that nastiness in your mouth. How many glasses you will need to drink is anyone's guess. It depends on how long you manage to keep each glass down and how much SN actually gets absorbed into your system. It will be some sort of a guessing game, really, if you have enough into your system to be successful.