Two possibilities spring to my mind for you. Let me clarify why I am recommending them.
Both of these hypnotists have a female speaking voice.
Both have files that can include feminization, but do not involve any extraneous males. By that I mean no sexual linking to males or any inclusion of such a scenario taking place.
Both seem to be fairly strong at using their voice modulation to invoke subconscious reactions in listeners.
First hypnotist is Neverside Labs. All of their files are available for free from their website. Due a google search for the site.
Pros:
Seems to understand voice modulation to stimulate reactions and involuntary nervous system responses.
All files are given for free.
There are no hidden subliminals attacking who you are or demanding loyalty, etc.
Each session seems to have been well made.
Cons:
There is only really three "feminizing" aspect triggers. One is the common "good girl". One gives the "patient" a session-use girl name of "Alice" to fit the Alice in Wonderland theme - however, not everyone enjoys having a hard set name applied. And the final one only has the user drop into a dream world where you are Alice and experiencing everything from a female perspective.
The wonderland file includes triggers which are initially installed in other files, and those files require yet other files. In other words the only true feminine feeling file requires listening to four other session files first just to correctly install triggers used in it.
Even the wonderland file is somewhat limiting. You are given a default outfit to match "Alice" except its an Alice that wears a pink hoodie over the petticoat skirts. But other than that if you have a mental image of Alice in Wonderland then you can guess what "you" will look like. You'll also see the room around you as a typical "princess / girly" room.
Second hypnotist is M1str3ss M@r1s@. Downside her files are not free, and also eventually get retired from her site which makes it tougher to get hold of just the files you want. For the pay site google the name above without the l33t text censoring followed by the word hypno after her name.
Pros:
A sexy voice that she uses to put sensual scenarios into listener's fantasies.
Understands how to use multiple voice layers to both reinforce suggestions and bypass defenses.
Understands how to change voice patterns to illicit reactions subconsciously of listeners.
File names are usually quite descriptive, and the files do not seem to contain any hidden surprises that fall outside of this stated purpose.
Each session is self contained, no prior files needed. However, they still assist each other.
Cons:
Paid files only. This means you either need to pay out of pocket at her website, or hope for a seeding here in a thread - and then you're dependent upon others for what you get.
All of her files attempt to at least on a small scale link your future pleasure with her sessions. Not for everyone as a result.
Most of her files seem to have an incestuous leaning to them - motherly or sisterly- which is great for some, but not for others.
There seems to be a minor prevalence of some kinks such as foot worship which again is not for everyone.