...therefore i'm guessing it needs cleaning!
I've just washed the bedsheets and instead of coming out lovely and white they have dirty streaks across them that weren't there before

I have run my finger around the rim, and there does seem to be an element of scum (have nasty feeling it's grot from DPs football kit and DSs pooed on clothes)
How do I go about cleaning my washing machine? I've heard white vinegar might be good, is this true? Any advice very much appreciated!