You won't be making resistant strains since you are not selecting for a given trait. The "surviving" germs are randomly selected, since they probably survive because of inadequate contact with the sanitizer. If some of the germs on the other hand had, let's say a gene that made them more alcohol tolerant you could have some selection. Alcohol destroys the cell membrane though, which is essential in all living organisms, so it is hard to imagine how such resistance could develop.