People used to rub charcoal and allsorts into their strops to make them slightly abrasive. My great grandfather used a straight all his life, my grandfather said he (his father) didn't use a hone at all, Gramps thinks he rubbed ashes into is stop.
Here are two pictures of them one with my Great great grandfather
sorry if I'm off topic, but one of them is the oldest straight user you'll ever come face to face with:D
In the group photo the baby is Grampa, the Lady is My G G Grandmother Ma' Bennett (she had a renowned chippy)
There
The second picture is Grampa in uniform during WWII, he was on the landing craft. Not a nice job I'm told. He is 84 this year.