The guys are all americans and the liquid C from Kitsandmore is probably the cheapest source of C inside the USA. And getting it from inside the USA to avoid any trouble with customs got obviously pretty important after 9/11 and the homeland security madness.
Liquid C, if one keeps it in the mouth and it is mostly taken up by the muscous membranes there IS more effective then swallowed as this avoids the so called “first pass metabolism” - say the C is not metabolized and partly (about 40% IIRC) destroyed by going first through the liver. It also comes up faster, but thats not so really important with C which works best the next day anyways.
Taking C and V together at the same time is not the perfect way to do this. Better is to take C lets say in the afternoon and the next days evening two hours before the act a small amount of V. 10mg C and 25mg V - that should suffice nicely. This provides the best of two worlds - practically no sideeffects from neither of the two drugs, the prolonged time of action from the C and the almost raging hardon from V, but not so bad to loose all sensitivity.