Is grounding with RCA is safe?

I see. Thank you all for your inputs. 

I searched online and learn that ground loops can destroy audio gears in long run. Is it true?

I still have a question regarding your reply: 
"In effect what you are most likely doing (depending on the designs of the components) is connecting the internal circuit ground of each component to the chassis of that component and to the chassis of every other component in the system"

I check the ground box from Entreq. It looks like to me that they do the same thing.

Could you help shed some light on this?

I have to apologize for my ignorant questions because I am a dumb in electricial area.

Thank you.

Thank you everyone for your valuable inputs. I never thought that I could get this much help from audio community. 

So if I understand it correctly, what I am doing this is 99% safe. Besides, doing this can compromise the accuracy of the system.

However, I'm concerned about the 1% for my audio gears and safety of people around me. Also, I don't want to mess up with the accuracy of the system. Therefore, I am thinking about a DIY passive grounding box, which is a wooden box with different minerals inside. I think it does not take much time to turn what I am having now into a  DIY passive grounding box. 

Not to take sound quality into consideration, do you think that this solution is safer and less interferes with the accuracy of the system?