HR with crack is hard cause it's a very compulsion based habit, with little planning and patience involved:
And Crack is way easier to find in the city so sometimes that's all you're gonna get.
And sometimes, it's 4am when you cop so you're stuck with whats in the house.
And Outside of the UK, your average user doesn't have Ascorbic acid packs laying around.
I usually just add a little bit of distilled vinegar then water for my solution. It's a rare thing for me, but never had a complication. Just don't miss or "boot" w/ coke shots.
(I did notice when making speedballs w/ BTH, it would naturally back down. )