I had great success with behavior modification (no charts though) but only after we'd put The Explosive Child principles into place. My child was also younger than yours at the time and I used it in limited situations to get over the biggest hurdles (severe anxiety) or for behaviors that were really important like brushing teeth. For an older kid discrete methods like marking a tally on the calendar might be better if you do it all.
When my kiddo was younger he responded very negative to parental praise. As parents of difficult child's we spend a lot of time trying to get them to cooperate and I think he felt like he was being manipulated.
If your difficult child is 12 and raging at every little request I'd go for The Explosive Child and really get a handle on that first.
