I have a Koken Strop That I have used for a while. I used a very small amount of Fromm strop conditioner on the hand finish imported shell horse hide No.1 selection & it has worked like a champ.
The linen side is very stiff fire hose style strop. I cleaned it with Oxy-Clean & let it soak for a few hours. The strop is pretty clean but still very stiff. Is this a treatment some makers put on the linen?

Slawman