I went through my first heroin withdrawal about three-quarters of the way from Singapore to Baltimore, at a Super 8 motel in Romulus, Detroit (airport). Five days of indescribably terrible hell on a bed of sweat, tears and diarrhea.
Of course I'd been using Southeast Asian number 4 heroin, best in the world, every day for a year and a half. I'd always heard withdrawal was terrible, but before I went through it I was like, "Yeah, right, sure, uh-huh...". Told myself before I went to the airport that if I got uncomfortable on the plane I'd simply eat some of the 10mg valium I got from my doctor (I had about 60 of them with me) and maybe have some stiff drinks too. I was sure I'd be fine.
Long, repulsive story short: the benzos did absolutely nothing to help. I remember eating them like candy, taking 60mg at once. Might as well have been Pez I was eating. And my idea about the alcohol? I couldn't even hold down a small glass of water thanks to the rapidly progressing withdrawal symptoms. By the time I made it to the Super 8 room in Detroit I'd eaten almost all of my valium to no fucking avail whatsoever.
So no, they didn't work for me. And neither did the clonidine I'd received at an airport emergency clinic. All thatI had was time, alone in the dark on a motel bed, going through agony I'd never even come close to imagining existed. But it all depends; there are many factors that determine your withdrawal. How good the stuff is. Your age, general health, gender, mental state...so many variables. Good luck however things turn out.