A tube? Like a funnel cup or something? I've seen people use a straw but the goal is to get down as much as possible in as little as possible to overwhelm the redutcase hemoglobin enzyme, which leads to the rapid rise in MetHb levels.
Your call if you want to use it before or after, just don't eat anything. Take a couple of mints before drinking it and then spit em out, drink the sn and take those same mints afterward to deal with the taste, at least that's what I'd do.