does vinegar and tea tree oil kill virus or just bacteria?
Yep, about 80%, so in line with bleach and other cleaning agents. A double rinse during this time is most probably advisable.

Just makes me think about the environmental effect of disposables even more. Can you image all these virus poo nappies in land fill, being rained on and the water running off into the water tables. Ew! At least with cloth, it's going into the toilet, where it belongs and can be treated.