Here how it works: bad behavior produces negative points and grounding until the points are compensated by duties that generate positive points.
Eg. Micha forgets to do his homework and gets bad grades consequence 200 - points, he can now choose which cores he can do to offset the 200 - points. (see below link for examples)
To further motivate I even created an exchange rate to boost his pocket money 3 points = 1 Euro.
It has worked wonders for us and has taught him skills.
Good luck
https://docs.google.com/spreadsheets/d/1FfL_aeNpfNPpnjDL1wQiVHB0kHywakR1hzjWk698SVA/edit?usp=sharing