Following a recommendation from Ihants, I came off the A34 at Litchfield and continued south towards Whitchurch, parking in a lay-by at SU462522, the unfortunately named "Clap Gate".
The walk starts a few steps north of the lay-by, up a thin track through the band of trees that marks an old roman road. It emerges from the trees onto a broad farm track across fields and through woodland before plunging back down a similar footpath into a further band of trees.
The place was deserted with little sign of human traffic except on the farm track. The wheat must be close to harvesting so it'll get busy any time soon and then there are clearly pheasants being managed for shooting.
I stripped off in the cover of some trees and walked back. I found the farm track a little daunting so I walked along the edge of the neighbouring fields with plenty of cover from a large hedge. A bit of a moment when a helicopter flew low over the edge of the field but I pretended I had my shorts on and it kept going. Could even have been a police helicopter... Back in the wood, despite being nervous about the lack of visibility, I walked to within 100m of the road before redressing.
Great feeling and a very pleasant walk.
I find as I approach that moment when I am going to take off my clothes I cant think about it. I also have to undress in cover, which is a little odd given that I then walk out naked into the open.