What can be done to clean out the inside of the iron as it builds up the chemicals that are in the water. I have a great old panasonic iron that I use for large pieces after washing them but sometimes it spits out a light rusty colored water for just a second at the beginning of ironing. Can you run a vinegar bath through it like you do in a coffee pot or is there a product to use that will clean out the inside. It is either that or I will have to go get me another cheapy iron.