Good morning, Maria, and thanks for asking a very important question.
Your question indicates that you have researched the employment barriers that may stand in the way of your husband's participating in treatment. Here are my suggestions:
First, verify that your husband's employer or health insurance provider does not offer an Employee Assistance Program. EAPs generally provide an outside evaluation and referral service on a confidential basis and can also help your husband ask the employer for reasonable accommodation time-off while he attends a treatment program. If there is an EAP, ask your husband to contact it for assistance.
The "reasonable accommodation" phrase is relevant here. An employee who voluntarily seeks treatment for alcohol or drug problems may be classified as a disabled person eligible for reasonable accommodation under laws that protect against discrimination. Ask an attorney about this; I am not an attorney.
You might also encourage your husband's union and employer to seek relevant information from authorities within the larger union or local/state government agencies responsible for administration of anti-discrimination laws.
Finally, many community-based treatment programs offer services at several different times of day, to accommodate those participants who must continue working while in treatment.
I hope this information is helpful and wish you and your husband well.