We have been doing SEO since 2005 and had more than 50 such clients who are into escort niche.
We have worked for many Escort Directories like OAD, Massage Republic and others. Although working with escort agencies based out in London and other European cities is absolute fine work, as they usually prefer to spend money on good quality Guest postings. Where as for some Indian and Asian continent clients, they always preferred to us to go for FREE link-building techniques(Off-page optimization)
We have a client from India who had website they started in 2012 and we did the work on that website till pandemic strikes in 2020 beginning. We selected their preffered keywords and created some Free link building using various guest posting by using our connection.
Although it was a huge task to find the guest posting websites who accept to add links to Escort site.
The main thing when you do guest posting is, how clean your client website is, is it neat and user-friendly, attractive or not.
So keep in mind, you should create a website which is well structured, user-friendly and more over it should publish realistic content and not just some SEO-over optimized content.

Also to tell you that getting the website on top 10 or even on top 3 is actually dependent on planning and continuous effort.
In recent times we had another client who approached us(in November 2023) for an escort website SEO to be done.
We did a thorough research for his requirement, asked his client persona, the kind of escorts they offer, and what will be their target in means of users.
A research of 30 days and a planning of keyword, site structure, design and some content.
A perfect Technical work to engage in highest page speed(99 score in PageSpeed) with right choice of keywords.

When all was done we pushed the INDEX,FOLLOW meta to make it accessible to search engine.
We did not make a single Backlink to it, no Off-Page work initiated till then.
It was launched on night of 3rd of January and BINGO!
The website started ranking within 24 hrs of its launch for some of the handpicked keywords.
I am attaching the snapshot of Google Search Console.
1st : Impression on the next day of launch (18 impressions : Day 1)

NOt just Impressions; We have a nice Click-through(As we handpicked the right keywords for them) The CTR is above 16% in very first month(And its rising)

The CTR:

although it seems Tricky without The ranking position of the website; Here is the snapshot for the Rankings:

Here is a rough details about the first week Average Positions:
Day 1: 6.3
Day 2: 3.2
Day 3: 5.7
Day 4: 8.8
Day 5: 3.5
Day 6: 9
Day 7: 5.1

Below are the snapshots:
Day 1

Day 2

Day 3

Day 4

Day 5

Day 6

Day 7