I keep forgetting about the 14 day thing. Though I do tend to try things first and, like you, have found the MBG on opened foundations and expensive skin care invaluable.
The last thing I returned was a set of Shokz bone conduction headphones. I must say I thought them great for me as I can't stand earbuds and full on headphones give me a headache. However, Mr. AE complained of noise leakage so back they went. (I'm always complaint of noise leakage from him but he won't let me send him back to his mother
) A shame really as if I still walked the dog they would have been ideal. They're excellent if you're out alone and need to be aware of your surroundings.