The gold or silver will eventually wear off the fabric, but Hoffman and others try to make sure that the fabric will still look great down the line even after the gold/silver wears off.
I don't give it special handling other than to minimize how much it rubs against other fabrics in the washing machine. (Front load is easier on fabrics than a top loader, and short cycles are easier on fabrics than long hot cycles.) The gold and silver will last a long time with reasonable handling.