Trade school is a better choice for these type kids .
That is about the dumbest thing you can do IMHO. Let me ask do you want a plumber , HVAC service tech. or electrician who failed out of school in your home working ? Do you want them adding up the cost on your invoice ? Would you want the risk of a not so smart person doing work that not only could lead to your being uncomfortable or worst sick because they were not smart enough to do the work correctly ?
I say this after 40 years as a tradesman in three trades as a Master and journeyman. And 8 years teaching trade school at night and about 11 as a appeals board member for the county building / court system.
Consider if plumbers do a poor job there are not enough doctors and nurses to cure the infected .