I use "No, Thank You" keep walking. I've had the door alarms go off on me a few times when some hidden strip didn't get de-magnatized. I just looked straight ahead and kept walking. No one bothered me.
I at least turn around and see if anyone is telling me to return. Typically there is nobody paying attention, or somebody sees me not doing an Usain Bolt impression and just waves me out. I dont necessarily mind being stopped when that happens. That is at least a reasonable suspicion something is up.
Better than just stopping me for S&G with no RAS.