Excellent piece, Holly! I just penned one for a website about how to make your own dildo, which was more about what items at home you can use to pleasure yourself when you don't have access to traditional sex toys. It was intriguing to research.
I think most women have grabbed something on hand to help out. Before I owned sex toys, my go-to was the handle of a brush!
But back to your experience, a woman I was friends with in the past was a US marine. When she was deployed, she made sure she had one of the vibrating razors with her and used it for masturbation. Apparently it was fairly common for female marines/soldiers.
I've also heard of women using electric toothbrushes for the same reason. Discretion and pleasure <3