Any game hacking will involve a chance of getting banned.
Not single player, that's nearly impossible because they don't care you aren't too concerned with that, when you memory hack in single player, you're basically doing it for yourself and others aren't really affected, therefore COD isn't going to waste their time detecting SP hacks. However for MP I totally agree, there a good chance of ban of whatever kind of hack you use.
WARNING: Skype name is "fastifan" without live, dots, or any other characters. If you are to contact me on Skype for transactions, confirm you're talking to me on MPGH first.