I have a ten hour layover in Singapore, connecting from HCMC to Houston. My plan is to head out into Singapore for food and a walk around before going back to the airport about 3 hours before my flight. Does anyone know of a place in Changi where I can pay to have a shower, change clothes, etc? I know there are transit hotels, but I really don't want to pay $230 for a room for a couple of hours. I just need a place to shower and prepare for that long flight. Thanks.

Depending on which terminal you are in they do have transit lounges with showers that you can access if you pay. Should be able to find out more on the Changi website.

Other option, there are cheap hotels in town which will rent rooms by the hour. I did this once for a similar layover.

I've used the Plaza Premium Lounge showers in T1 before. You can book ahead of time or just walk up. If all you want is a quick shower there are cheaper showers in T2.

I'm actually flying out later today and going through Changi on my way to BKK.

Do you have any airline lounge access?
I've showered in the Singapore and Qantas lounges before.

I don't know about Singapore but I have used the pay shower in Taipei. I'm sure they must have something similar at Changi.

It's been a while but we paid to use the pool in T1, which also had shower facilities. Looks like $23 per person.

https://www.changiairport.com/en/airport-guide/facilities-and-services/swimming-pool-with-jacuzzi.html

FYI, I checked in at the Plaza Premium Lounge at ~7am this morning, and the wait time for the shower is about 1.5 hrs. You get 3 hrs minimum lounge access as well for 75 SGD.

Pretty entertaining video about Changi Airport if you understand Spanish.

Eggs and kaya toast is the Changi breakfast of champions.

A real safe bet if you about to be on a plane for the next 18 hours.