I did actually buy some distilled water to use. Not sure if it makes much difference but, seems worth the effort in a way.
Personally, I'd avoid any type of food- including candy. I think I'd have a bottle of mouthwash on hand to try and get rid of the taste. Again, not really sure if it would make a difference. Not sure about acidic sweets in particular. They advise not drinking fruit juices with it because of the acids. I think it turns the nitrite into nitrate. Probably wouldn't be a large enough quantity to do much but, I just think I want to take as few risks as possible really. Seems risky enough as it is.
But, I'm no expert. There are likely people on here who know more than me.