As the disease progresses, people with dementia increasingly require assistance with Activities of Daily Living (ADLs), including hygiene and toileting. In long-term care facilities, caregivers are responsible for accompanying residents to the toilet, which is not only time-consuming but not pleasant for either party. This paper presents an automated step-by-step system to guide people with mild dementia in using the toilet. The user's actions are detected and then compared to a model that specifies the correct toilet procedure, which includes toilet bowl actions and hand-washing. When inconsistencies are detected between the user's actions and the model, interaction with the user is initiated. A multimodal approach and feedback from healthcare professionals are used to tailor the interaction of the system specifically for users with dementia. Experimental results validate the functionality of the system to recognize actions performed by the user and provide suitable instructions to the user or alert a caregiver.