I knew when my kids were doing drugs. I'd always been observant and involved. First thing I did was get us all into counselling - not just them. Parents who toss their kids into counselling over drugs are completely missing the point.
Testing kids is, I agree, a band-aid, and not worth the money. Kids will always find a way to get around it. And what about the parents? The scariest thing I ran into during the counselling program was the attitudes of alot of these 'parents'. The holier-than-thou-do-as-i-say-not-as-i-do approach. Any problem with any person in a family is a family issue.
Drug tests can point a finger, but they definitly will not solve the problem.
"Our lives begin to end,
the day we become silent,
about things that matter"
~~Martin Luther King