Detox serves only one purpose......a few days to get the drug out of the body. Its not a cure and depending on the drug he uses the difficult physical aspects may still be present if hes only been in since Friday..........
Yes, outpatient treatments will and do drug test........but again depending on the DOC that may or may not be dependable.........if instance if the DOC is crack and he uses it on Friday but doesnt go to Op till Weds the test most likely will be negative.
You asked if he should come home to you and the kids................thats a question for you to decide but what I can say is I would be prepared to continue to deal with his active addiction because he hasn't found recovery yet....hes only dried out
a few days.............
best of luck to you and your family