It is possible ask them to leave thier watches on the side.

Have a box for them to leave their phones, keys, watches and glasses etc

I more worry about them having a recording camera fitted in it so it would be recording when they came in until they left. I have thought of an airport style box but I felt a bit daft and that I might offend them. I suppose il just have to do it. Don't want to send your heads west girls but keep an eye on their watches and you'll see they follow you   

Lucy I think you may be over thinking a bit....

I would definately rather over think it than have someone tell me I'm all over porn sites or outed on a forum. My anonymity is the most important thing for me ever, I have too much riding on it.  I think I'm being a bit OTT too but it's naive to think it's not going to happen to someone at some point. Technology is advancing and there will always be people exploiting this.

Yes you can get cameras in plenty things, it's 2017.
Several ways to minimise something like this happening, when they take off their clothes hang them up in a wardrobe for them and close it, or fold them onto a chair, when I am doing hotel incalls I always pop their clothes in the wardrobe just out of politeness.

You could always ask the clients to take the smart watch off and explain why, he may be using it to track the calories he burns in sex lol, I do this with my Fitbit sometimes!
I think if they were using their watch to film they may be doing movements with their hands to get the view which may seem strange, if they are genuine and have nothing to hide they shouldn't have much of a problem taking it off and putting it on the side because of your suspicions.

Also don't leave clients alone in the room. Of course there may be someone out there who's done this or will do this but in my opinion I think it's more likely a client will use a phone slyly to do it and not a watch which is much much more obvious. X

when someone comes to me i say leave everything on the desk  no phone or camera allowed in the bedroom end off...

I do the same. Being a bit of a tech nerd I can tell you there are smart watches with cameras even at their sides. If someone wanted to take shots or to film they could find ways to do that using all sorts of devices hidden in clothes, even glasses. They could also do that during a welcome greeting. Hell they could even plant a device in your bathroom. I think the chances of people being so indiscreet are low, and the chances of people going to such extreme lengths are even lower. There is no point becoming paranoid, risks can ever be eliminated, but they can be minimised with common sense precautions.

Im banning watches as of tomorrow, I have been unconfortable with them for a while