I've CWE'd paramol many, many times, and on the last few occasions, really couldn't feel much from even 2 boxes. I've pretty much burned down every chemist in a 5-mile radius: I look dodgy (foreign-like, all Jewish and swarthy & intense), but not like a druggie, and I didn't think they were suspicious of my abusing the paramol. In fact, concerned pharmacists of every age and race in four different (small, independent) chemist's eventually took me aside, and said 'look, if you're in this much pain you should see a doctor and get it checked out, taking this much paracetamol isn't good for you, and the doctor can prescribe you pure codeine.' I tended to CWE when depressed/hungover, so I probably did look pretty pained, and several of them had filled prescriptions for me for antibiotics (been on them 5 times in the last 12 months), so they must have been wondering what the hell was wrong with me.
I often gazed longingly at the codeine linctus just behind the counter in one shop: but I noticed it only long after I'd started over-buying paramol there, sometimes with diphenhydramine ('yes, I know I can't take them together, honest, guv'). The pharmacist there, a lovely but very conservative Sunni Muslim guy in his 60s, was the first to suggest, when I bought one box too many, that I go to a doctor and get something prescribed, though he did NOT refuse to sell me that box. He did say that they'd been advised to RESTRICT how MUCH people could buy, if they kept buying it - not to stop selling to them completely, but to ration them - and that he wasn't going to restrict my access YET, but that he was concerned that I was popping pills, rather than getting treatment for the cause of the pain. So I don't think he would have been terribly keen to sell me linctus of any opiated kind. I felt like such a FOOL when I noticed those lovely little 200ml bottles sitting there - I could have bought at least one, when I first moved here.
Eventually, he also became uneasy about my buying diphenhydramine. Had to stop going there for anything non-prescription.
I'm generally shameless about such things as buying porn in newsagents, lube in chemists, women's underwear (for girlfriends), or whatever, but I just don't want to risk refusal of linctus by a chemist.
And like a lot of posters here, though I last used heroin 5 years ago, and that was a first-in-ten-years, I just can't, after some very nice times on a CWE, get enough out of codeine or dhc, even with diphen-promethazine cocktails to potentiate, to justify the hassle of a CWE. I found paramol to be the only OTC painkiller worth abusing, and when two boxes carefully filtered only chill you out slightly, there's just no point continuing.
Now, on the rare occasions that I indulge, I'll go with pods. I'm not crazy enough about morphine alone to bother with J Collis Browne's. It's just 10mgs per bottle, right? I find pure M more powerful than most - did 3 x 10mg doses of oramorph over an hour and a half, while in great pain from an impacted wisdom tooth infection and an allergic reaction to amoxicillin that had my face swollen up to the size of a basketball. It was a far more stimulating hit than pod tea, and in no way just a 'weaker heroin' - it has a particular character, and there's a slight edge to it. 30mgs, which as I understand it is considered a low recreational dose - though another forum advised 5-10mgs without tolerance - was strong for me, and when it first peaked, I did have a second of thinking 'if this gets much stronger, it might not be a good thing.'
I was a little paranoid, having, last time the infection flared up, ordered some hen & chicks pods and, like an idiot, became impatient for the effects to kick in after 90mins or so, and brewed a 25-pod batch. Weekend of kidney pains, constipation, and, surprisingly, insomnia, followed. From what I've read, it was probably a borderline OD.
Sorry for the long post. I smoked something that wasn't tobacco an hour ago, and it seems to have gone to my head. So, in conclusion, yes, 'twere a better thing to be in the US in this respect, and have access to easily controlled doses of hydro and oxy: though from what I've been told, the latter might be a little too stimulating for my tastes. Used to be a speed freak, but these days I like to chill. Sadly, can't get any downers that aren't zopiclone.