Your biggest challenge OP isn't actually your son, it's how you are going to find the support
you need to provide the kind of compassionate, gentle and open minded support your son will need from your support. However, in terms of what your son needs or may benefit from, consider the following:
Without the proper medication, you son is going to have a very tough time if he just stops taking opioids. I'm thinking of the new job. Frankly, he's likely to start using again if he stops (or already has) for that. Without the right medication, this is very likely.
Calm Support is not the right medication. Medication prescribed to treat the opioid detox and early period of abstinence include: gapabentin, clonidine, buprenorphine, methadone, diazepam, baclofen, loperamide, etc. There is no reason he shouldn't be working with a doctor on detoxing and addressing his mental health/substance use disorder condition(s).
Don't expect anything significant from products like Calm Support. Short of kratom, DXM and loperamide, OTC meds and supplements are of very limited value in this process. When push comes to shove, the biggest benefits of detox remedies like Calm Support are largely placebo (then again, this shouldn't be underestimated). Other than that's their claims are entirely marketing.
What is it your youngest son wants in terms of his drug use OP? Has he expressed he wishes with you, and in particular how he wants to try and address his problems? As a general rule, being open and supportive of his wishes in terms of recovery/life are some of the best ways someone can help a loved one struggling with substance use. If you want to be supportive of your son, you'll have to be very respectful of his wishes and goal in this, and to avoid organizing his treatment or recovery for him.
Whatever you do, I'd suggest educating yourself about ORT (buprenorphine and methadone in the US). Please visit the
SL Directory to learn more about these treatments, particularly
https://www.naabt.org/faq_answers.cfm?ID=1 and
https://drive.google.com/file/d/0BxuNdydJNzUmV0hqZjRzd2hYRFk/view.
It is important to echo that treatments like methadone and buprenorphine ARE NOT at all like trading one addiction for another. It's not even accurate to say that it's comparable to trading one dependency for another, at least not for the vast majority. Idea like those are little more than the product of misunderstanding, corrupted messages of abstinence only based approaches to recovery and generally folks who do not understand the first thing about treating opioid use disorder.
I will caution you that working to support family can be INCREDIBLY challenging but incredibly rewarding as well. It will however likely require you work on your own misconceptions surrounding substance use however, not to mention all the baggage than family - for better and worse - bring to the equation when trying to support their loved ones.
Please don't get the wrong idea. Family members who really stand by their loved ones, particularly their children, are indeed saints. So many families are far too quick in my culture to disown (whether completely or more subtly) their loved ones once they learn of their struggles with drug use or identify them as an addict. Recovery is very often a process of coming of age (in fact, it is really best thought of as a developmental process), particularly for younger folks. Families who provide a safe space for their loves ones to figure their own process out are not the norm, and deserve tremendous credit.
Speaking of the nature of recovery, you should definitely read Maia Szalavitzs' book Unbroken Brain. It will give you a really great understanding of what your son is going through, even if you've been through something similar with your husband before.
And on that note, I'd also suggest giving this entire thread a read:
http://www.bluelight.org/vb/threads...ddicted-to-Heroin—And-Shaming-Me-Doesn-t-Help
