I would suggest shutting off your hot water tank heater and cooling it. Then use the isolation valves to isolate it. Remove the drain plug, and then stand out of the way, and lift the safety valve. Water should shoot out of the tank.
Now what you need is a thinner hose that will fit into the tank through the drain plug opening, and spray water around in there from outside as it comes out through around your spray hose. This is attempting to get the pink from the tank.
After that, fill the tank up partially, and drive around a bit to slosh the tank, then drain plug again and let it all out.
After that, either one, or the other, or both, you might get to the point where you don't notice it.