having much the same problem myself.  and am trying everything - extra rinsing, tea tree, hot wash... we are still stinky!  any idea welcomed!

~bump~

As well as a good hot wash, once or twice a week i wipe over with a little lavender oil. ( I put this in with the wash so nappies come out clean ) i just put a drop on a kitchen towel and wipe over, hey presto nice smelling wraps.

see i do all that... 60 wash... vinegar etc... i rinse all the nappies out then put them in my bucket B4 washing.... I think what started the smell thinking about it was, i went into hospital with Twin1 and my fella left the nappies in the box for a week YAK i know... and used biodegradable throw aways...

Nice hot (60 degree) wash with 1/2 the regular amount of powder and a slosh of white vinegar in the fabric conditioner section - followed by a good blow out on the line in the sunshine.

For stained nappies I'd usually just give an overnight soak in some nappy soak  (like PHP nappy soak) followed by the hot machine wash - but i'd normally only soak the dirty ones, not the wet ones. They don't always look spotlessly white - but any given stain will fade over a few washes (and dries in the sunshine) and at least i know they're plenty "clean" enough to use again.

I wouldn't try using anything not designed for fabrics - as you never know what reaction your lo might have to residue left behind on the nappy - or what it might do to the waterproofing on your wraps.

add soda crystals when soaking- thats suppose to stop the stink also can be washed using this.

tea tree oil when soaking is suppose to help but i never find its strong enough.

Hiya... How does every1 stop their wraps from stinking... for some reason they stink of stale pee... infact its the whole nappy not just the wraps.... would soaking them in milton help?? i have no idea how to get rid of this smell... advise would be greatly appreciated.. Can u even put the platic bit in milton???