I actually disagree slightly with some of the above posters.
I think a cheat meal NEEDS to be "all out". If you are strictly dieting, then your body needs the kick that a high-carb and even high-fat meal.
As for worrying about salt - I could care less about salt intake, esp in a cheat. Salt-related water rentention will go away in a few days and if you drink enough water on a day to day basis, the retention is minimal.
Dieting is hard - strict dieting - emotionally and physically. Sometimes you emotionally need a day/meal that allows you to eat whatever you want.
If you are strictly dieting and you have an ALL OUT meal once a week, or once every 10 days, that can only help you in my opinion.
BTW, MY idea of a cheat meal would be pizza and ice cream, pasta and cheesecake, or burgers and fries. If you are going to do it, do it big.