Dann is still fuming about the way Ngog dived to earn a penalty - and a draw - on Monday night.
And he reckons it is time the FA came down hard on the guilty players.
Dann said: "The only way you can stop it is to suspend cheats and it's up to the FA to sort it out. We all know diving goes on but no one likes to see it. I'd never dive to win a penalty. David Ngog is not the only one who has ever done it. A lot of it goes on and it is disappointing. It is a tough one for us to get our heads around.
"People say they are not sure what can be done to stop it, but rules can be changed to clean up football - and people have to be punished heavily.
"Everyone who saw it knew it was a dive. I am just sick because I had family and friends there and wanted to put one over on Liverpool.
"But we can take some consolation in the fact that Ngog had to dive to stop us beating them."