cleaning a mattress

[pud1]

I have taken dd out of night time nappies and she has had an accident. Her mattress smells of pee. How can I get rid of the smell. Don't want to buy a new one until she is fully dry at night. I am away all weekend so it will have plenty of time to dry out. Thanks in advance

Can you take the top layer off?

My ds decided he wanted to try nappy free and had an accident - the mattress had a layer you unzipped and it stopped spills getting to the core. The removeable layer went in the washing machine and the core outside for the day with the side he slept on facing the sun.

Other than that sponging rather than scrubbing -perhaps bicarb for smell - and then outside for the day to air?

No zippy bit unfortunately. I thought bicarb might do the trick