How is the foam made in a Turkish bath?
An attendant can use a cloth bag and soap to create a large volume of foam. The foam wash is a different step from the kese scrub.

Related questions
What is the difference between a scrub and a foam wash?
The kese scrub exfoliates with a mitt. The foam stage uses soap and washing movements. A menu may include both, but they are not the same treatment.
Will the soap be rinsed off after the foam treatment?
Rinsing is part of the washing sequence. Tell the attendant if soap remains or water feels uncomfortable; do not wait until the treatment ends to speak up.
Is an oil massage included in every Turkish bath?
No. A traditional scrub and foam wash can be booked without an oil massage. Compare the treatment list, not just the word “massage”.