I don't know about the kilo claim... years ago I had to extend the waste hose on my mum's washing machine. She tends to do 30 degree washes. The gunk does build up in the hose.
One day I had to deal with it- that pretty much means that I removed the pipe from the sink end and blew through it until the gunk turned up in the drum. I have since recommended that she does a 90 degree wash from to time.
Our machine must be near 12 years old now, and last year I had to do the drum bearings - of course I did a thorough check whilst it was in bits, but there was no signs of any build up anywhere, all clean as a whistle. Default wash, is a low temperature one.