Background: Otocariasis, the infestation of the external auditory canal by ticks, is a common presentation in endemic regions and an emerging clinical consideration in Australia. Conventional agents, including local anaesthetics and oils, often fail to rapidly inactivate hard ticks, potentially prolonging patient discomfort and increasing the risk of infectious complications. Dimethicone, a non-toxic, low-viscosity organosilicon compound, has demonstrated efficacy against arthropods but has not been evaluated for hard tick otocariasis. Methods: In a laboratory-based experiment, 48 Rhipicephalus haemaphysaloides ticks were randomly allocated into four treatment groups (n = 12 per group). Each tick was submerged in one of the test agents, and the time to complete inactivity was recorded. Observations were performed under magnification by blinded investigators. Data were analyzed using SPSS. Results: Dimethicone achieved the fastest mean inactivation time (75 seconds), significantly outperforming olive oil (753.3 seconds), coconut oil (1056.6 seconds), and 2% Xylocaine (no inactivity observed within 1800 seconds). Conclusions: Dimethicone rapidly and reliably inactivated hard ticks in vitro, outperforming commonly used agents - potentially due to its ability to penetrate the tick’s spiracular system and block respiration. This low-toxicity compound may offer a practical, effective option for managing otocariasis, particularly in outpatient and emergency settings where rapid tick immobilisation is required. Further in vivo studies are warranted to confirm clinical applicability in the Australian context.