On Tue, 20 Sep 2016 21:54:38 +0000, Stormin' Norman
wrote:

Has anyone here encountered such a heavy scale situation previously? If so, how have you dealt with it?

You have toilet cooties.

Follow the acid method in this link.

http://www.wikihow.com/Fix-a-Slow-Toilet

Danny D, Bob and me will attest to the veracity of the method.