AMS - Both are part of the hotels but offer a "shower only" rate to the public

"YOTELAIR
Simply drop by and see us at YOTELAIR. We're located on the upper level of Lounge 2 in piers D and E, next to the food court. We have 2 shower cabins available to rent for up to 1 hour, at a cost of € 15. For more information, please visit the YOTELAIR website.

Mercure Hotel
Visit us at the Mercure Hotel Reception. We're located on the upper level in Lounge 3 in piers F, G and H, opposite the KLM Crown Lounge. The shower costs € 19,50 to use, and the price includes a towel and toiletries. For more information, please visit the Mercure Hotel website."