I have a 6 yr old boy who is also adhd and i do give him his space to play for his exxxtra energy but it seems it never ends .I know that punishing doesn't work but there has to be some boundries or they just take over...my boy has straight A's in school so they won't give him medication ..I cant tell u its not easy im a mother of 3 and there all boys so its crazy here , but yes there has to be lots of rewarding ,but most of all lots of love and understanding...and remember keep the faith ...
stop punishing him, and start rewarding him. The worst thing you can do is timeout, corner chain, the silent treatment. Start rewarding him by telling him that if he does't use curse words for a whole day/week/hour however frequent it is, you'll sit and do something that HE wants to for an hour or two. I've been trying to rebuild my relationship with my mother lately, and I was an ADHD child who got punished ALL the time. Take it from the son's point of view, we harbor this anger and these resentment for a long time, so bottome line.....START rewarding, and STOP punishing.
How old is your son? Have you got him doing a lot of sports and Physical activities to get rid of some of the surplus energy, is his Dad involved with Ball games and fun, does he copy anyone else in the Family "cussing" he will do it if he hears it. How is he at school do the Teachers find his behavior okay.