You have asked your question in the hepatitis c forum. No one here is a medical professional. For other blood borne viruses as in the associated forum or better yet ask your doctor.
Viruses are not germs by the way.
I found this with a google search about peroxide and hep c:
“Alcohol, hydrogen peroxide, and kitchen sink detergent (for example, Dawn Ultra) can kill hep C. But they are all less effective than bleach, and require multiple rinses to kill hep C. They are good options when bleach is not available” This was a description of how to clean needles for injection by drug users.
Note: only about 1 percent of the population has hep c so first one of that small percentage of the population would have to have used the bottle prior and any blood in that bottle would have been in the solution for a long time and probably killed by then. It might be simpler to ask your friend if they have any blood borne illnesses.
Or since this was a preplanned activity probably should have brought your own materials along as well as the piercing ring.
Or better still have a professional perform the piercing as they usually provide this service for free with purchase of earrings.
When I had my ears pierced they used alcohol.
But anyway I really doubt you would have any concerns about hep c.