Even though he's not letting me know yet still give it a try?
I think I would wait until he’s letting you know every time.
I would use them. It could be a while before he reliably lets you know when he needs to go. Just keep reminding him and one day you realise that you don't have to do it all the time anymore.
We are using them and cleaning up the messes 🙃 not sure if that helps