Absolutely. Once, at initial interview and possibly any time at random, just like a job. I see people everyday selling their food card for .50 c on the dollar for the ability to buy disallowed items such as alcohol, cigarettes and lottery. The EBT card should also be able to be used as a bus pass. This would make it possible for users to go to a real grocery store instead of the little neighborhood markets that charge double because they know you are walking or are captive audience. It would also make the person think twice about selling their groceries and transportation. It would be more valuable to keep it.
I agree, it would cost a little to do this, but not as much as you think. When I see some of the account balances on these cards of a person that has a number of kids, and to think it's being abused, it would be an excellent investment.
I would not pay for rehab. They blew it, they pay. However, they can attend free support groups such as AA or NA and others and they will all sign or stamp verification of your attendance.
One blown test, you do the above. The second time, lose your card for month.
Then with the verifications and a test, reinstate the card. Third time, you're out.