You will never know till you ask! I have no problem asking for permission, but I usually wait for the right timing like cool hand said wait till you catch the owner outside, at a store, etc.. If you are looking at multiple properties at once and are patient the right time will usually come up for each one. But sometimes you just have to go in cold and its either going to be yes or no. My experience has been usually yes but make sure you do not leave evidence that you were there because not only will you not be allowed on that property but might loss future permissions. I would also recommend to never dig round plugs.