I have to agree that from what I have read about subs it would be foolish for one to get on them in an attempt to kick codeine. Why get on a harder opiate to kick a weaker one? Especially since codeine is legal and cheap anyway.
Crankinit, from a HR perspective I would say start off an opiate naive person on 200mg or less. That said, the few people I have turned on to it only really enjoyed it at doses 350mg or above, I have been doing a LOT of reading on codeine lately and theres some forums where people crap on its dangerous to combine like 120mg codeine with 5-10mg valium and the like. My experience has never been that anyone would get any appreciable effects at such low doses. I tried CWE a few times like 5 years ago, always at doses below 200mg and it didn't take me many attempts at those doses to decide it wasn't for me. It was years later I decided to try higher doses and thats when I fell in love with it.
Codeine is really hard to determine what to start people on, because there is the odd person that can't handle the nausea from low doses, but I always feel as though if I don't get a decent dose in someone on their first or second try their probably going to write it off as shit. You know your friend better than us, if they have used a reasonable amount of drugs in the past, particularly if they have opioid experience, and aren't the type to be overly sensitive I would aim for 300-350. If there isn't much to go by then keeping it at 200 or under is the smartest thing from a HR perspective.
I would like to comment on mr ibis saying diphenhydramine was a good potentiator for opiates. I am not sure if this is allowed but I am not naming specific sources or prices so I will try my luck, if anyone is interested in diphenhydramine you can buy it behind the counter under the brand name 'snuzaid', It is an OTC sleep aid similar to restavit, the pack is almost identical but it says snuzaid insted of restavit and all the parts of the restavit box that are green are blue on the snuzaid box. I am pretty sure theres 10 in a box but it might be 20, they contain 50mg diphenhydramine.
I happened upon these when one of my regular pharmacies had run out of restavit. When I first read of using antihistamines to potentiate opiates diphenhydramine seemed to be the most commonly mentioned by Americans but I had trouble finding it.
Anyway, I am sure the masses of people aren't wrong that overall diphenhydramine is a great potentiator for opiates, but the only opiate I have used it with is codeine and it kills the high. I read it inhibited CYP2D6, much like promethazine. I favour restavit because I can dose it before my codeine and never have to deal with the full extent of the itch, stuff like promethazine annoys me because I have to deal with the initial itch.
Anyway, I have never had a problem with promethazine killing my high if I wait about half an hour after drinking my codeine to take it. Anyway the one and only time I used diphenhydramine to potentiate codeine I used it in the same manner I have promethazine in the past, waited 30 minutes or so after dosing my codeine to take the antihistamine. My codeine was just starting to come on when I took it and within 15-20 minutes my high was totally dead, like not only did it not continue to come up but the mild initial feeling I had was gone too. It is a fucking antihistamine and the only effect of the codeine I could still notice was the itches! It was extremely frustrating. I have kept the diphen to try with other opiates, I have used heroin and morphine lately but since I have been combining them with codeine I haven't tried it yet.
Anyway, this ended up a bit of a rant. But yeah, I don't personally reccomend anyone tries diphenhydramine with codeine. If you are determined to try it wait as long as you can after drinking your CWE solution.