Run an empty load with hot water and use a cup of vinegar instead of detergent. Make sure you clean out the detergent cup and around any seals or gaskets. Once the cycle has run, wipe out the inside of the machine with a water/vinegar mix, and let it air dry with the door/lid open. Vinegar’s safe for clothes, so you don’t need to worry about rinsing or re-cleaning it before your next load of laundry.
If you try all that and it doesn’t work, repeat using half a cup of bleach instead. As always, I think bleach is generally overused and underdiluted, so save this only for if the vinegar doesn’t work. As bleach will discolor your clothes, either run another empty load or one with whites when you’re done.
Comet is bleach (technically cyanuric acid, which is a component of bleach), and BKF is oxalic acid, which is primarily used for removing rust and other stains on metals. Short version: Comet is good for scrubbing and bleaching, and BKF is good for stubborn stuff on metal and non-porous surfaces.
I’m not a chemist; I was trying to break it down into the basic differences between the two. I apologize that I didn’t get the chemical name correct based on the information I was using from the MSDS and allowing myself to be influenced by the marketing that put “with bleach” on the front of the Comet can and didn’t research more thoroughly.
Someone just steered me to a Jezebel post about a TLC program about a woman who bleaches everything in her house (and in other people’s houses), including food and, well, everything. My two strongest reactions:
1. Holy fuckballs, does Gawker’s commenting system blow goats; and
2. You do not ever need that much bleach. Even in sterile lab settings, you’ll almost never need a bleach/water ratio any stronger than 1:10. And most of the time, bleach is overkill. I’m (obviously) not a scientist, so I’m not going to speculate on breeding supergerms or whatever, but it’s not good for your skin, not good for your respiratory system, and generally unnecessary unless you’re dealing with biological hazards. Bleach has its place, but it is way overused, and please don’t bleach your food, people.
Is the blue thing actually bleach? If it is, you don’t really want to use anything else until it’s gone. You could always speed up the process by putting some gloves on and fishing whatever’s left out of the tank. Once it’s gone, a few days’ worth of flushes should clear it out just fine.