ΔE 25.8, loose: different enough that you should pick on purpose. Nuln Oil is a little darker, much more muted than Strong Skin Wash.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 26). Nuln Oil is a little darker, much more muted than Strong Skin Wash.
The same difference applies the other way round: Strong Skin Wash is a little lighter, much more saturated.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Strong Skin Wash on the colour wheel See Nuln Oil on the colour wheel
All matches: Strong Skin Wash equivalents · Nuln Oil equivalents