Diazepam hands down. For me I have to have a pretty high dose of it during acute WD and then reduce it quickly so I don't become benzodiazepine dependent again.
Then again, I take alprazolam in addition to the diazepam. But yeah I just make sure to spread the diazepam total daily dose over at least 4 split dosing times just like methadone for pain management, because yes it has a half life, but the actual duration of relief that you feel will be less than if you stack your dosing like I outlined and it keeps a steadier level of diazepam and it's metabolites like nordiazepan which has a 750hour half-life, they'll all build up and it won't take away more than 50% of the WD symptoms and you'll be lucky if it helps even that much but I know how when kicking people can justify using excessive amounts of other sedatives or even stimulants to take their psychological mindset away from the focused-on-your-withdrawal/detox-pain, but the efficacy of using a lot of benzodiazepines is really not going to increase with the dose you take, so try to keep it as low as you can and don't expect it to be like something that in any way agonizes your opioid receptors so it doesn't really do anything biochemically to directly impact opioid withdrawal, keep it in mind.