Waterproof sheet smells of wee

[CraftyCrafterson]

Just started putting dd to bed without pull ups and she's had an accident over night. It didn't wake her so goodness only knows how long it was on the bed but I've washed all bedding on60 degrees and the waterproof sheet smells even worse than before it was washed!
It's on the line now but is there anything that will take the smell out? I can't put it back on the bed like this

[CraftyCrafterson]

Oh and I washed it in 60degrees with bio powder