I am neither a dog owner nor a resident.
I've been following the local versus non-local dog debates. 
It seems to me that the focus has been on the wrong area. There are responsible visitors and irresponsible residents. I have friends that visit here for two months and are scrupulous about bagging and removing waste from their dogs. 
The owners of the home next to us never police their yard. They have the cleaning staff do it after their visits. I assume that if they don't bother to clean up their own property, they don't bag waste anywhere else. I think the crux of the problem is people not cleaning up after their dogs, period. Leave out the distraction of residents versus non-residents. 
The process of getting dog tags should be made more accessible and better publicized. More tags would be bought leading to more funds to address the real problem — cleaning the beaches of undesired dog “reminders.” Set the fees at a reasonable rate for all. Few people visiting for a week are going to spend $70 for a tag, responsible owners or not. Good owners are simply not going to get the tag but will continue to clean up.