Once the emulsion remover is soaked in it'll be time to scrub!
In screen studios they use power washers so you could use that if you have access to one. You could also bring it to a car wash.
I don't have access to either so I will use green brillo pads and scrub it off! Older screens are more susceptible to ripping so apply pressure as you see fit. Keep applying photo emulsion remover where necessary.