Smelly nappies! please help

My nappies stink of wee! I have washed the entire stash 3 times with extra rinse and still some of my Inserts smell? What am I doing wrong?

[clothmama]

Hi and welcome @chloebear+milliemoo

What are the inserts made of? Is it just them that smell? Are you doing a cold rinse - hot can set smells? A soak in a bucket of water with some white vinegar added overnight can help, I believe that bicarb also neutralises smells but I've not used it personally.