There is a general license in islamic theology that when it comes to life and death situations you are allowed to break almost any of the rules temporarily (survival overrides close to any other religious obligation/rule).

This includes eating pork and drinking alcohol (say if they are the only food beverages available, or if you need to drink alcohol to manage exceptional medical conditions). So it is likely you can make an argument for alcohol as disinfectant if it is the only one available with its impact/cost.