For patients who are uncircumcised, there is usually sufficient skin for a vaginoplasty without using any scrotal skin. Preoperative depilation is not usually needed. Theoretically, there may be some hair growth at the opening of the new vagina, but this area can be easily accessed and treated post-operatively. Where scrotal skin is to be used, hair removal is strongly recommended. If it is not done, there is the risk of complications from hairball formation, and it is seldom possible to remove the hair permanently, as the skin from which it grows is high in the vaginal cavity.
Pasted Graphic
The area which should be treated is shown in the photo; the scrotum is being held forwards, and the anus is at the lower margin of the picture.

In London, I recommend Sara Thomas, who has a weekly session in the GIC on the Fulham Palace Rd., as well as rooms in Harrow. Her website is at; gender transitions.co.uk, where her contact details can also be found. Whilst laser and IPL can achieve satisfactory results, I think electrolysis is the most reliable modality for permanent hair removal.