I asked my ps about them and he said they can be expensive and usually you can't tell if they're helping or not.
I Have Seen Some Women Talk About Silicone Strips After a Breast Reduction. Do These Really Work?
Doctor Answers 2
Silicone Strips for Breast Scars
Silicone sheeting has been demonstrated to help improve the appearance of some scars. Having said that, it is my experience that the majority of breast reduction scars heal well without silicone strips.
Since it is unlikely to do any ham to use them, if you are willing to put up with the expense and inconvenience you could use them. If not then the odds are you will have a reasonable scar without.
Silicone strips and scarring
There is a fair amount of scientific evidence that they can help scarring. They are not cheap and can be a bother to use as they have to be worn almost 24/7 for 3-4 months. Only you can decide if it is worth it to you. Good luck!