One way would be to use a tracker-app (Strava, Fitbit, etc) which would give the distance, along with a video of the naked walker plus a quick 360 at key points to show where you are.
It would be hard to post online due to the size of the video file, but sounds a fun option.
Plus “Bonus Points” for walking in non-nudist areas and areas/time with more chance of “normal” members of the public
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