Korea

Korea - mini brain dump:

Korea has kissing booths, spas, and ktv.

• kissing booths:

"Basically a building with a big K label and you pay a set fee for either 25/30/60 minutes and you get sent to brush your teeth and then you have a full room to yourself and then a girl will come join you. It’s hella awkward at first because it’s just a random Korean girl and then you basically start making out GFE and cuddle and then do anything extra for a tip or if they’re into you they’ll just do it without a tip in mind. -AdemiGod

• ktv - you go to ktv and get girl, you pay for time there and then go afterwards, depending on location you can pick girl or not
• spas, these are similar to soaplands in japan, example maruspa.com or dioranma.com

These places are generally discoverable via Google OUTSIDE of Korea, or if you are in Korea via a VPN to outside of Korea. Inside Korea on a regular network it's harder as the government isn't exactly a fan of these places.

As far as servicing foreigners go:

• in my limited experience, no issues were encountered as long as you were well dressed and groomed.
• I speak almost no Korean other than hello or goodbye.
• places do take walk-ins just fine, no appointment was needed

Other things:

• US military: ditch the uniform, and anything that stands out
• grooming, reminder on this, they care about fingernail cleanliness etc
• credit cards worked at most places