Months for roots or years for full recovery I meant
Orchids take their time, especially after being stressed like this.
Sphagnum moss works for many people when recovering orchids like this, because it's nice and humid, but you must be careful not to water it too much, otherwise it'll become super soggy and will just help kill the suffering orchid.
Still, there is no guarantee that this little guys will make it, even if you do 'everything right', unfortunately that's how it goes. We all have lost an orchid or two (or more :P).