1) Per the ruling of you Marja (Sayed Khamenei)’, if the alcohol makes one drunk and it is originally in liquid form then it’s Najes.
2) According to Ayatollah Sistani, all these types of industrial alcohols are pure (they are not najes). Hence, the hand sanitizer dropping on clothes does not make them najes. But based on the fatwa of your Marja’, he says if the alcohol is originally in liquid form and it makes drunk (meaning if one were to drink it then it would make him drunk) then it’s najes.
If you have doubt about whether it’s najes or not, the law of purity applies and you can consider it pure.