Emerging assistive technologies represent a potential resource for supporting older adults with dementia and their families. However, developing useful and effective technologies is challenging as it is particularly difficult to run prototype tests with potential users from this population; tests that are necessary to ensure the unique and complex needs of this targeted user group are appropriately complemented. This research investigates the possibility of using actors to simulate older adults with dementia to optimise technologies before they are used in clinical trials, thus potentially circumventing considerable time, financial, and logistical obstacles. To gauge the applicability of this approach from the perspectives of human experts and assistive technology, examples of six older adults with dementia and six actors simulating older adults with dementia participating in the task of handwashing were shown to professional caregivers and to COACH (a computer-based assistive technology). Data from believability rating tasks by the professional caregivers and interactions with COACH were compared for the older adult with dementia and actor groups. Results were promising with both the caregivers and COACH showing little difference between the people with dementia and the actors. While these preliminary findings are encouraging, the small sample size of this pilot study necessitates further research before definitive conclusions can be made.