Time is money. People are way more expensive than equipment. You gain more in terms of productivity/salary cost if they take the laptops home. Start by assuming the equipment is a lost cost that you're never getting back. If you're proven wrong then it's a nice extra.
To mitigate risk slightly you can prevent someone from taking the equipment home for the first few months of employment. New hires generally have to spend the first few months proving themselves before getting benefits like that.