In the home, each family member should use his or her own nebuliser chamber, this is for hygiene reasons.
In theory, PARI nebulisers could be used by several patients. However, according to the hygiene regulations currently in force, this is not permitted unless the nebuliser can be sterilised (e. g. in an autoclave in a hospital).
KIV, boiling in water, cold water disinfection tablets (e.g. Milton tablets) & 'baby bottle' disinfectors do not sterilise, they just disinfect (this is a lower hygiene standard).