scrub board snaffle question

[Achinghips]

Are the ridges meant to go on the inside facing the tounge or the outside facing the cheek, anyone know?

 

[Solstar]

either way- i tend to put the ridges to the tongue as it makes it slightly keener when you take a contact, then the other way isn't quite as strong.

 

[Achinghips]

smashing - thanks so much for the response, will try it this way tomorrow, weather permitting!!!!