Here is an easy solution:
Pass a law that dictates the only job the guest workers can do is to hold targets at gun ranges. Instead of stapleing your target to a board, a guest worker takes the target out as far as you tell him/her to , and holds it up above their head. When your fineshed, they bring your target back to you. Pay them $5.00 a day. If you accidentaly kill one of them, no biggie. Their not officially here anyway, so technicaly you didn't kill anyone. If one does die from work related injuries, his/her pay goes back to the gun range for maintenance costs. There will always be another guest worker to take the dead ones place. If there are more guest workers than the existing ranges can handle, the government will build more to accomodate the guest workers.
I think this is fair.