'No Point' Grading Homework
So, don't factor homework in the grade. Don't even collect it. Assign it of course. Design the tests to be challenging for someone who has done the homework.
If students don't do the homework themselves and struggle and learn, they will fail the exam. Problem solved, the unfit won't progress.
My Calculus professor didn't assign any homework. On the first day of class, he simply handed out a double-sided sheet of paper packed with lists of problems from the textbook, which had the all the answers in the back, and said, "If you don't do every problem listed you probably won't pass the exams and class." I did every problem and the practice helped.