The Club charges $25 to use the shower for 30 minutes. No clue about the cleanliness or water pressure. Google Reviews mention towels not being replaced or taken away in between uses, which leads me to believe they don't clean the showers too often.

The Centurion Lounge shower has really low water pressure (their sinks too), as part of a "water saving" program. (I've complained at the front desk a few times.) It may be an airport-wide initiative, so The Club's showers may also be low, too.