Kabukicho rule no. 1 - Ignore the touts. There are soaplands in Kabukicho that cater to foreigners but Don Juan & Barubola are on the expensive side and they also add gaijin tax. IIRC Max is the only soap that doesn't add gaijin tax in Kabukicho.
As for Yoshiwara, some providers have Twitter/X accounts. Some of them explicitly state on their profiles that foreigners are ok. If you guys contact one, tell them upfront that you are using Google Translate (if you don't speak Japanese but I think some are ok with English). Also, tell them ahead if you are cancelling. One of the shops has started requiring foreigners to come to the shop & pay 1 day before the appointment due to no-appearances from gaijin customers.
No soapland in Osaka. There is a Mat Health - Club Amour. Since it's a health service there's no FS, but there are reports online of some providers giving that service. CyrillFiggis is correct, better to ask on TAG, but read some threads first before asking there.
Reminder that THC & its affiliates has been banned in TAG due to fake reviews and some other reason.
Lastly, make sure to wear face masks when going to known establishments/red-light districts in Japan. There are YouTubers/vloggers who do walking videos or live streams in places like Kabukicho & the shinchi areas.