I have a couple of 10 Litre steel jerrycans which I used for draining kerosene (UN1223 28sec burning oil) from a tank. After disposing of the kerosene I left the open jerrycans upside down over some oil-absorbing pellets for a couple of days.
I would like to re-use these jerrycans to store unleaded petrol (gasoline) for my car - which is what they are designed for. Do they need further cleaning or is the tiny amount of kerosene residue unlikely to do any harm.