James 3:8
"but no man can tame the tongue. It is a restless evil, full of deadly poison."
James 3:9-12
"With the tongue we praise our Lord and Father, and with it we curse men, who have been made in God's likeness. Out of the same mout come praise and cursing. My brothers, this should not be. Can both fresh water and salt water flow from the same spring? My brothers, can a fig tree bear olives, or a grapevine bear figs? Neither can a salt spring produce fresh water."

It's either one or the other. You are still a salt spring if you have even an ounce of salt. I can't imagine the kind of practice and strength that it takes to be a fresh water spring. Taming the tongue is vital. "Out of the overflow of the heart, the mouth speaks." Matthew 12:34

The heart is where it can all start. That's where the change can really begin.