It would be a bad idea to take food before or during SN, it slows the absorption of the poison and it increases the acid level in your stomach which also negatively effects it. I don't know exactly how SN and milk interact, but since SN reacts very badly with juices, I wouldn't risk it with milk either. Someone who ctb with SN recently had hard candy to suck on to help against the nasty aftertaste. Maybe you can try that?