what you are proposing is not acually dogging, it is a meeting, more, a "cardboard" glory hole sounds somewhat contrived as we can't see it surviving long in the wild so to speak. Would this by any chance be a home made glory hole at your residence or similar and are you actually asking for a lady to meet you to play out a glory hole fantasy?
If that is the case, we would suggest that , 1. Your post is a little too ambiguous and 2. It is in entirely the wrong place!
Good luck in your endeavours, however our opinion (and it is simply our personal feeling) is that you need to be quite clear what you are proposing.....thats why we were all taking the "rise" out of your first post.