Manchester City and Paris St Germain both face heavy sanctions from European football's governing body after being found to have exceeded FFP limitations.
"You would think that you accept the rules and you're in the competition or you don't accept the rules and you're not in the competition," the Arsenal manager said. "Then, everybody would understand it."
Wenger has long advocated a need for clubs to live within their own resources, having been powerless to see first Chelsea and then City challenge for top honours bankrolled by the deep pockets of billionaire owners.
The Gunners manager feels UEFA should simply get tough.
"There are rules. You respect them or you don't respect them. If you don't respect them you have to be punished," Wenger said.
"When UEFA doesn't want to kick the clubs out of the Champions League, they have to find a more subtle punishment. From all of us on the outside, it looks a complicated punishment, which nobody really understands.
"We live in a society where everyone is informed. The rules have to be clear that you can inform people well. If I go out in the street now and I ask 100 people what you think of the (UEFA financial) fair play punishment, how many do you think can explain it to you? I am in the job and I cannot do it.
"They have to clarify the punishment. We all agree that if we don't respect the rules you have to be punished, but to explain to people how that works is very difficult."
Wenger believes the current set-up shows "there is something wrong", but accepts unless there is a collective drive for change, it will be very difficult to secure a lasting positive impact.