I am almost to scared to post this incase you all think I'm some feral who doesn't do washing but...

One of the inserts for my cushie tushies has gone mouldy...

This particular one has probably been used twice. The first time I used it prolly sat in the bucket for 24 hours before I washed it (which I didn't think was an overly long amount of time) and then I hung it out in the sun for the day, bought it in and noticed then that it had a couple of black dots on it, but I just assumed it was something that came off the line and didn't think much more of it... I have sinced used it again and done the same thing and the dots have multiplied

So, why!? And how can I get it out... I have washed it, and the others it was with twice and then with super hot water but it's still there, none of the other nappies that it was in the bucket with have gone mouldy, just the one insert...

TIA for your tips!

Mwah!