How to identify customers who only purchased the try-on dress?

Our bridal boutique offers a program where you can order a dress to try-on before buying it:

https://queengowns.com/products/at-home-try-on-rental

I know that I can easily filter orders to see who purchased this by searching “try-on”- BUT I really just want to identify the customers that have purchased the try-on and ONLY the try-on- which means they didn’t come back and purchase a bridal gown yet. I cant figure out any way to do this. Any suggestions?

Thanks so much in advance!