I heard about periochip for periodontal disease, what do you think about this product?

Helpful addition. Periochip can be helpful when used in conjunction with traditional treatments for periodontal disease like deep cleanings or periodontal surgery, and can reduce the amount of bacteria that cause periodontal disease. Used alone it is unlikely to provide any benefits of significant result. The best person to see to find out if it will be helpful for you is your dentist or periodontist.
Sometimes. It may work in very select cases, but once the chip dissolves and is gone, the causes of your periodontal problem reoccur. Periodontal disease is a bacterial infection. Antibiotics do not work long term due to bacteria developing resistance. Bacteria replicate quickly & get back to pre-treatment levels. I use perioprotect=significantly reduces bacteria daily, & bacteria cannot become resistant.
It's okay. Periochip is chlorhexine made into chip form which you place inside a periodontal pocket. That said, I don't know of too many dentists/periodontists who use this b/c there are other products which are as effective and easier to use.
Has a role. Periochip (chlorhexidine) is an excellent adjunct in helping to treat some periodontal problems.