We'll admit to not being up to date with the details of how such clubs work ourselves but we do think that this is rather an odd thing for anyone to be complaining about:
The popularity of sex clubs is by no means restricted to Kent, but local authorities around the country have limited powers to regulate the activities of consenting adults.
The purpose of regulation is, or at least should be, to deal with the effects on any third party of what consenting adults might get up to. Thus the not in the streets and frightening the horses type of regulation is just absolutely fine and dandy. But other than that there not only isn't a need for regulation, to regulate is against the very purpose of the body politic itself.
For the purpose of government and the body of regulation it erects is to enable consenting adults in their activities. The regulation of those third party effects is only, solely, to enable those others to also enjoy their lives as they see fit without bearing the burden of the choices of others.
That is, regulation is there to increase freedom and liberty by preventing its denial. We may not like that some deploy such liberty in the pursuit of enthusiastic non-monogamy but that's an irrelevance. The social contract demands that we tolerate it, as we do so much else, up to and including the existence of Simon Cowell.
That is, the whole of the game is that the authorities have limited powers to regulate the activities of consenting adults. As long as all are consenting, all are adult and all is in private then there should be no such regulation.
That's actually the point.