Do not remember any in Wanstead and lived there for years, Manor park is gone, Libbys still there though not been for years, One above shops in Goodmayes Lane I think it is still there, I heard Gants Hill had opened again, my sis in law ran it for a while. Last time I passed there was still one on Leyton one way system. One in Hackney but long time since I was that way. Hornsey road had one, no idea if still there.
There was a sauna on Wanstead high street for a number of years, at the junction near to Snaresbrook station. It advertised in local newspapers and on the web, with a cheaper (no entry fee) HE service available 24/7 (as 'Anna of Wanstead'). It was owned by 'Clyde' who went to jail with his Ukrainian wife for various prostitution offences, they also owned the similar branded ones in Leyton (Annabel's) and Walthamstow (near The Bell pub), plus the old Lolitas brothel on Leytonstone high road (which didn't charge an entry fee but had less girls on):
External Link/Members OnlyAfter the raid they were all rebranded as 'Body, Mind & Soul', I popped in once and enquired, it was usual £10 entry fee and negotiation with girl for assisted massage and a body scrub, an glum EE quoted me £70 for a HE massage

They didn't last five minutes. The Leyton one, which was for years next to an Islamic Cultural Centre, is now part of the expanded centre

(the sauna branding still evident on the windows)
I'm surprised Crystals in Leyton held on so long, given the competition with Annabel's over the road.