Leave em in the garden over night, kick em around the grass and mud a bit.
Thats the first thing I do with anything new, hunting clothes wise anyway.
Obviously a t.v would not get the same treatment.
Never wash them unless you cant get the b.o out by thrashing them around the garden, even then only wash without detergent ect, then when clean, yep you guessed it, kick em around the garden again and leave em out there to get aired off.
For me masking sent is equal if not more important than camo.
.atb. .ste.