Hi ! I'm really glad you reached out to ask about this. We have a lot of community members here talking about Efudex, and there are many grey areas like this where you're not sure if it's done its work.
This is one place to post, where some members have been talking about Efudex: https://skincancer.net/forums/efudex-fluorouracil.
Another great resource, as we can't really advise you ourselves, is our advocate April Pulliam who talks about each stage of the process here: https://skincancer.net/life-with-skin-cancer/my-journey-with-efudex-in-photos. It includes pictures that might be useful. Of course, each body is different, and if you're really looking for a yes or no, you might want to reach out to your doc or a PA.
Hope this helps you! - Nina, SkinCancer.net Team