a) the languages usually indicate what they can speak (to some extent)
b) going to their "room" is cool.... that's how many work.
c) some will advertize something like "45 min, unlimited ML".
You can search for services like that on
www.darling888.com ..... they have a search engine for various "pleasures".
I've met many gals that do not speak a word of English.... but they generally know what you want..... and are typically good at what they do!
smb02