I used 3 in 1 oil on the leather honing strap, I know now I should have used mineral oil. Did I ruin it or can I clean it somehow and apply mineral oil now?
There's no need to clean it or to apply mineral oil. Early versions of the honing wheel would delaminate with certain oils, but for the last four or five years, the glue used in the lamination is impervious to most petroleum distillates. Just use honing compound about every 2 or 3 tools and hone away.