Do I Need a Medical Mouthwash for the Rest of my Life if I Got a Dental Implant?

I have never recommended this or heard of others suggesting it.  While it may be a good idea to keep your mouth as clean and healthy as possible, the implant will NOT fail if you don't.  Once an implant has osseointegrated (fused to the bone) it will act almost identically to natural teeth (a bit more rigid).  You will brush and floss like regular teeth.  Using or NOT using a rinse won't make or break the treatment, if an implant fails later on, it likely has little to do with using a mouthrinse.

During the healing phase of implant therapy, every and all effort to keep the area clean and with minimal bacterial exposure is a good idea.  A lifetime commitment to a mouthrinse is not a requirement.

A daily mouthrinse is a proven benefit as part of a person oral health routine. There are brands that work and brands that don't. Ask your practitioner if there are any other brands you can try that he/she is comfortable with.

Your dentist is wise in encouraging excellent home care around your implant to preserve its health long term.  There are a variety of mouthwashes that can help control bacteria on the surface so you should be able to find a substitute from what you were given that you may like more.  In addition to brushing and flossing, the Perio Protect system is the most effective adjunct I have found to maintain gum and bone health around implants and natural teeth.