I think the idea is to never let it dry out, either keep spraying it regularly, or spray it to revive if it dried e.g. overnight. What I understood was it's safer because it's wet and traps the fibres. Depends on the ambient conditions apparently.
There was a webpage somewhere I read it, let me have a search!
Edit: Hmm can't find the one that basically said keep it wet or re-wet it later, but check the video at bottom of this page:
Home Strip X-Tex from Eco Solutions. A solvent-free super strength artex remover and stripper for walls and ceilings. Buy direct or find your local stockist.
www.ecosolutions.co.uk
Basically, do everything you can to let the moisture soak into the surface.