Yikes, how foul are you? Me, at least a new pair per day. If a heavy work day, two. I understand some, at the end of the day throw them against the wall, if they don't stick, good to go.
https://nypost.com/2019/08/16/nearl...-pair-of-underwear-for-at-least-2-days-study/
https://nypost.com/2019/08/16/nearl...-pair-of-underwear-for-at-least-2-days-study/