Smelling nappies

Any one have problems with smelly Itti bitti's. Like big ammonia smell.

I had 2 AIO i sold on TM and The lady has washed them and she says they smell really bad.  And I gave advice of vinegar and sunlight and she says she's done all of this and stripping them and now she's saying as soon as her child wee's in them again the smell really bad and making him itchy and sore.

I'm not sure what to do about it. She's really disapointed.
I sold them cause DS soaks through IB within an hour.

Any ideas, of how to rid the smell.  

because they are AIO and you can't separate out the layers for washing??
This is what I suspect may be the cause. I have one more a moo moo one that even though is useless I just can't get rid of it. But if I have it right up at my nose and sniff yeah there's a bit of smell but nothing drastic. I wonder if she may be a bit OTT about them being clean.

Wash in canistan.

Also it can be detergent build up. So get her check to see if there is suds when they are rinsed without washing powder or the like.

Also i found my boy smells more since he went onto formula & reflux medicine.

That is what worries me when I want to sell mine. But if you say they didn't smell when you had them, it will be something to do with her child possibly.