www.irvinespa.com
ISpa (Irvine Spa) has partially reopened and is 10-15 minutes drive from Anaheim. I believe the showers, dry sauna and hot tubs are open, but the steam is not. I haven’t been back but BC (before COVID) it was always clean and well maintained. It’s a Korean spa, good for eye candy, but not really a place for actual hooking up on premises. In case you wondered.
You might want to call before going to confirm what facilities are open.