Experimental: Self-administered acupressure

Participants will attend a 90-min self-administered acupressure training session by a registered Traditional Chinese Medicine practitioner. A follow-up session will be arranged in the second week to reinforce learning and to make sure all participants can locate the proposed acupoints correctly. The follow up session will be conducted face to face (prioritized mode), or by phone/video call based on patients' preference. The acupoints are chosen for inclusion in the protocol based on literature review \[25, 29, 34, 35, 39\] and expert experience of the PI \[40-43\]. The location of acupoints (nine in total) include face and neck (Ren 23, Ren 24, ST5, ST6, ST7, TE17), upper limbs (LI2, LI4), and lower limbs (KI6). All acupoints should be massaged bilaterally except Ren 23 and Ren 24. After the training, participants are encouraged to self-administered acupressure on the acupoints twice daily for 12 weeks, each point lasting for 1 minute.

Active_comparator: Oral health education

Participants will attend a 90-min oral care education session in the first week by a trained research staff (the same frequency and duration as the intervention group). The content includes the causes of xerostomia, consequences, current preventative measures, dietary advice and oral hygiene advice.~Participants in the control group will receive a booklet documenting the content of the oral care education sessions. Throughout the 12-week period, participants will receive reminders of oral care for xerostomia twice weekly