Odor-resistant clothing…

I recently bought the Ex-Officio "no stinky", quick-dry undies. I must say – they were well worth the money. Awesome product.

But… my cousin said that after going through the wash enough times the odor-resistance goes away. Is this true?

(( there is already a thread similar to this, but i wanted to specifically raise the question of if it washes out or not, not wool vs. synthetic ))