Have a look in the washing and maintenance section for ideas on how to treat them for smells. Here is one I found that may help you https://www.bellybelly.com.au/forums...ut-smells.html

There could be a few reasons for the nappies being smelly but I find that they do need a strip wash every few months. You can find strip washing methods in the same forum as above.

I've had the following washing regime now for a long time and found smelly nappies aren't really a problem anymore for us but Caleb has all of his teeth. I reccon teething is a factor at creating that strong ammonia smelling wee that can linger.

I wash every second day and do a cold prerinse in the washing machine first to rinse out the urine and ensure they are being washed in clean water.
For the wash cycle I wash in cold mostly with a 1/4 scoop of Euca powder for detergent.
Once a week I will put dettol rinse in the fabric softener dispenser and that cycle I wash in hot.

Using vinegar will reduce the life of the elastic and delaminate PUL too so isn't recommended for regular use so be wary of that.