I have a build-up on the element in my Model #3114 Russell Hobbs electric kettle. I have boiled 50% white vinegar with 50% water multiple times. It pours out a green shade, and I do that mixture again until it's clear. The ill flavor is still in the heated water, is there a better way of cleaning it. This was an idea I had from my grandmother when she cleaned her percolators in years past. I'd love any idea!