Abstract: Attachment assemblies for oral hygiene devices and, in particular, attachment assemblies having improved designs to more effectively clean an individual's tongue or other inter-oral surface are described herein. These improved attachment assembly correspond, amongst other aspects, to improved fluid chamber configurations, improved fluid channel configurations, improved fluid exit hole configurations, improved air inlet hole configuration, and air channel features. Furthermore, these improvements to attachment assemblies are capable of being implemented separately from, or in combination with, one another.