graffiti questions

thank you for the information here. so if i see graffiti in a friend's town & clean it up for them, than instead of them seeing the mop, it'll show them a handshake instead, & i get righteousness points for cleaning up their town, but they still get xp & cash either way...? i just want to make sure i'm not taking away from my friends by cleaning up their graffiti instead of spraying more elsewhere or just finding something else to assist them with...!