Since it seems you've investigated the technical side of the problem do a little leg work on the human side. Talk to one of the security guards and find out who they report to since ultimately that is who your solution must be agreeable to. Explain the situation and ask what measures would be necessary to take in a device with a disabled camera. You can look at possibly using a case, skin or just a sticker that would obscure the camera just make sure that whoever the security guards report to OKs it.
Then the next obstacle is getting the guards to understand that it has been OKd. Assuming that there is probably a small number of guards that you'll deal with get to know them and preemptively bring the subject up to them, show them the steps you've done to disable the use of the camera and let them know you've talked to their boss about it.
Be prepared for them to still balk at the idea and have equipment around that you can use if they wont let the disabled camera pass. Hopefully at this point they will ask their superior about it and he will verify that he gave his OK and next time you'll be able to take your better toys in with you.
Just keep in mind that the security guards are just trying to do their job to the best of their ability. Things that will draw their attention and almost assuredly lead to your and your disabled camera being turned away/confiscated are any attempts to sneak something past them and any attitude at all if they ask about it. And by all means never wait until discovery/discussion of the device would interrupt court proceedings as that is just a good way to piss of a judge and get yourself found in contempt.