Seems to me like bupe is sort of... trying to open a jar by hitting it with a hammer. But, if you absolutely can't manage to slowly taper off codeine (you wouldn't even try with the help of some muscle relaxants or benzos? codeine wd isn't as bad as you think, as withdrawals go, speaking from experience) then yeah, I suppose bupe is an option.
Like Mad Dash said, you should never need to go above 2mg. 750mg codeine is equal to around 1.875mg bupe, using Wikipedia's morphine-centric chart as a rough guide (it's not gospel but it's a handy tool). 6mg would be way more than you would need - I've been taking heroin recently at doses that would be stronger than your doses of codeine, and I end up nodding on around 2mg.
It's not incredibly recreational, but it is to an extent, so I would be concerned that you would still enjoy it, and struggle to get off it.
Rather than increasing doses, you should be focusing on
decreasing them, surely. I can understand why heroin addicts for example, who need to go on big doses of bupe (that they can't jump on straight away) would need to gradually increase a dose to a high point like that - you shouldn't have a need to though.
I will warn you though, bupe has a very long half-life. The half-life of Codeine is 2.5-3hrs, whereas the half-life of bupe is 20-70hrs. The withdrawals are much worse, and last much longer. A friend of mine swapped their tramadol addiction for bupe, their intention was to come off it via a taper... two years later he's still on it. People often find the last jump to come off completely after a bupe taper to be extremely difficult, and a lot of people never come off it at all.
An advantage of taking bupe is that you would be saving your liver if you've botched your CWEs, but as long as they're always clear and you never use too much water then that shouldn't be an issue anyway.
I personally think you'd be taking a risk by putting yourself on a much stronger, much more long-lasting opioid. You'd be swapping one addiction for another one that would be much harder to kick - it's a very useful drug for some people, in certain stages of addiction, I just don't think it's appropriate for you. This of course is just my opinion, but bear what I've said in mind - I'm just looking out for you and trying to save you from the rough ride further down the road.
If you talk to your doctor about tapering Codeine, or even if you do it yourself with the aid of other medications (baclofen, pregabalin, or diazepam for example) alongside cold compresses, hot water bottles, lots of water, etc. to ease any withdrawal symptoms, that would be a quicker and less risky route to sobriety. It would be difficult, yes, but nowhere near as difficult as coming off bupe.
If your heart is truly wanting to quit, then you should be able to taper the Codeine down imho. Because if you don't 100% want to quit then you'll likely fail either way, and there's a high chance you'll just start using the bupe to get toasted. Plus, if you have to deal with the Codeine withdrawals then you're more likely to learn your lesson (this isn't a guarantee, but fearing withdrawals may help you to not become dependent again!)
Good luck brother, hope you get yourself sorted out
