Can I use ordinary soap on grimy shirt collars?

[CeliaFate]

I was thinking to rub Dove soap on dd's shirt collars before washing them, as they have already got a line on the crease of the collar that won't wash out.
Would that work?

You could try! I have a cream leather sofa which I use dove soap and warm water on to clean it and it gets a multitude of stains off so I swear by it!

Washing up liquid would do better.