Washing machine / Hard water

You might be getting magnesium sludge. Now that's not a scientific term or necessarily an accurate one but here's what might work for you.

Unscrew the hoses at the back of your washer, right where they go into your washer. Inside you'll see little round screens or maybe you won't as they maybe covered with a black kind of slime. Take them out and reverse flush them under another tap, that has some pressure to it, or alternatively, blow hard in the reverse direction to water flow and pick off the remainder.

Obviously this is only a short term fix. I think that to correct the problem permanently you may need a filter of some type, like an iron filter. But even if you have to do it for each wash day, it makes the job a whole lot easier.

Leaving a set of pliers beside the washer will make the job easier.

You might want to turn the water off first or maybe not. It would be kinda fun to watch if you didn't.