Many years ago I was told that the optical brighteners in most washing powders gave a brighter IR reflection than was desirable on combat clothing and that they should be avoided or clothing dry cleaned. Of course back then the uniform was cotton for its fire-retardant properties. (Which always struck me as a good thing!) The current uniform seems to be polycotton (?) and states on the care label "Do not dry clean" How should it be cared for to maintain the correct IRR standard? What washing powder should be used?