M.M.
Doing push ups will not get him to stop his behavior, but it will get him to hate doing push ups. I think it is good for his karate instructor, but not for home. You will have to find out what triggers him - find his buttons. This will take time & patience. Just remember, you are parent and he is the child. He is still at the age where he is testing boundaries and apparently he is winning. You need to take control back. Pick a punishment and be consistent - but NOT TIME OUTS (useless punishment IMO). Every time he is disrespectful you need to implement the punishment. If he continues, you remain calm and consistent (this is where the patience comes in). Do not engage in his banter - that is exactly what he wants you to do. He's only six, taking things away won't really do it either. A lot of people like Love & Logic. Maybe you could give that a try...