Let’s see. Summer school for high school juniors. PAY THEM to attend 3-4 hours a day. (un)Teach them all they were taught. My 8th grade history teacher was retired military. Let them work at McJobs before or after class. Test them afterwards for a bonus if they pass.
There’s more. Those that don’t want patriotism-centric learning can spend their summer in the 3rd world $hithole of their choice under the auspices of the Peace Corps. They might hate us even more but look at the alternative.
My earlier suggestion.