Effects of horsehair floggers

[T-Luv]

Wanting to include a horsehair flogger scene in an in-progress story, but having never used or felt one, I'm hoping somebody here would be kind enough to describe the effects (sensations, pain intensity, marking) of this implement.

In particular, I'd like to know how a pair of tender young breasts would react to a horsehair whip (poor little innocent 14YO girl with a wicked uncle.)

Would an extended tit-whipping (say, 15 minutes) with a horsehair flogger be a Really Bad Idea, as far as damage goes? The uncle usually uses soft whips that don't leave lasting marks, for obvious reasons, and I have no idea as to how much damage one of these whips can do. If it marks heavily, I don't want to include it in this story.

All help will be greatly appreciated!