Reply from our Silentnight Expert:
We don't recommend wetting the mattress or the use of detergents or chemical cleaners as it may cause damage to the fillings or mattress cover. If anything is spilled on the mattress we recommend using a cloth to absorb as much of the spillage as possible and then airing the mattress thoroughly to allow it to dry.
We recommend the use of a mattress protector on all mattresses.