Why often remedies do not work is common question.  Any individual native suffers due to karma of past birth as well as present birth. Normally remedies are prescribed based on planetary position, very often 6^th 8^th or 12^th lord or strengthening the 1^st 5^th or 9^th lord. But first we need to analyze is suffering due to own deeds called “swayam kruta” or its “vamsha krutha” if its swaym krutha its ok but if its vamsha krutha it has entire different process altogether.  One of reason why remedies don’t work is it do not match with person psych or tatva, . if remedies suggested based on tatva of person it has strong chances of success.