Would sticking your fingers into a bottle of rubbing alcohol after ejaculation as a means to cleaning them, would it contaminate the entire bottle?

Unlikely, but could: Rubbing alcohol kills over 99% of bacteria and other organisms. So, though it may not contaminate the bottle, i would presume it did. When using any bottled medicine, pour it into a cup, or on a cotton ball, and then clean the area. By the way, if there is even the tinest break in the skin, alcohol will cause severe burning sensation.