When i put cr ox and iron ox on some old leather i used the powder from whipped dog and mixed it with leather oil till it was like thin paint,i used a small paint brush to put on a thin coat and left it for a week for the oil to soak in then rubbed of any excess,not much came of because it was thin when applied and soaked into the pores of the leather making a perfect coating,the first lot i did was with ce ox and i made it into a paste and put some on then rubbed it in and rubbed of the excess,aside from being really messy i had trouble getting an even thin coat and it didn't work as i'd like