As in love and war, all is fair in dealing with them, in my opinion.
I had a particular problem with one local museum, as they have a general ban on photography, except for some select exhibits and events. Unless I contacted the museum management and got permission ahead of time, the staff at the museum would usually prevent me from even entering with my camera.
Anyway, I got to know one of the managers at the museum, and explained that I was actually trying to promote attendance at the museum, by posting my photos in a local online magazine on Facebook. She eventually came around, and liked what I was doing, and now she has given me pretty much carte blanche permission to shoot there. However, I still have to email her when I want to cover an exhibit, and she then alerts the museum staff to allow me access.
So it can be very frustrating in dealing with museums. You can encounter an entire spectrum of different policies that you have to deal with, depending on the individual museum. There is one museum and a couple of local art galleries that I have totally given up on, they are so hostile to photographers.
This is what the entrance to that museum reminds me of:
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This is a most sly and cunning idea that you have come up with. If this tactic fails, then my recommendation would be to get to know a key person in the museum's management. Perhaps you can convince them that you do not have nefarious purposes for bringing your camera gear with you.
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