I'll say this much for Hula House: it's delivered with total commitment.  As we enter the venue – a real Edinburgh tenement flat, 15 minutes' walk from the meeting-point at Zoo Southside – we find a naked woman lying on a sideboard, party foods scattered across her bare body.  We're invited to help ourselves (I confess, I didn't) and then settle down for a 45-minute exploration of the reality of casual sex work, focusing not on those who've been enslaved or trafficked, but on the women who drift into prostitution simply to pay their bills.

It's an important topic – but the treatment, unfortunately, is scattergun.  Sometimes the actors talk to us out of character, while sometimes they seem to be playing a role; we, too, are given a random name as we walk through the door, yet are expected to answer questions about our real lives.  There are all-good-fun party games featuring sex toys, which transition in an instant to dark and exploitative fantasies.  There's no obvious structure to of any of this – and so, rather than feeling startled or challenged, I found myself rather confused.

In any immersive performance, it's important to consider the relationship of the actors to the audience, and here that fundamental issue isn't quite thought through.  Much is made of the fact that, having bought tickets for the show, we've paid to see these two women perform; they draw a vague parallel to sex work, and ask us several times what we'd like to see them do in exchange for our cash.  Well, since they asked – I wanted to see them deliver a thought-provoking piece of theatre, ideally with pro-feminist themes.  Paying an actor simply isn't the same as paying a prostitute, and it's pointless to try to confront me over a baser motivation which I simply never had in mind.

The intrusion of the performers' own life stories is also rather clumsily done.  The aim is to highlight that sex workers' experiences and motivations aren't all that different from anyone else's, but by reminding us continually that they are only actors, the two women put an awkward distance between themselves and the stories they're trying to tell.  It grows a little lecturing, as well; an early quiz section is an interesting ice-breaking device, but in no sense is it site-specific, and it wastes the fact that we've walked for fifteen minutes to a flat dressed up as a brothel.

The frustrating thing is that Hula House is far from irredeemable.  It's a deeply well-intentioned piece, clearly based on solid research – and there are some ideas built into it which could be a foundation for strong, challenging theatre.  It also judges its audience interaction well, coming uncomfortably close to the boundaries without ever humiliating anyone.  But it needs to be far crisper in its concept – to focus more on a specific message, and commit more to just one or two of its numerous competing devices.