In reply to Mr Fuller:
Good instructions. The only thing I'd add is that, if the clothing is very dirty (with obvious body oil areas around neck, cuffs and shoulders), then a detergent wash may be required to remove the ingrained oil & dirt, followed by a soap wash to remove traces of detergent. This is Event's revised instruction after it transpired that Event can suffer pore contamination with prolonged use, as did first generation (PU-free) Gore-tex.
The one top tip that I would stress is
make sure your washing machine is spotless, and clear from all detergent gunk and residues throughout the entire water path. The easiest way to ensure it stays this way is to use and in-wash dispenser, so the water path never gets contaminated...
Gore's instructions have, for many years, been pretty poor ("use any soft detergent from the store"), and only seem to confirm to me that the vast majority of Gore-tex users really don't care about the DWR, and therefore don't care about breathability.