If you don't care too much about the scales' finish, here's the best way to do it:
1) Give it a good cleaning with an antibacterial cleaner or soap (including between the scales) to scrub away all the accumulated soap residue which may protect some microbes. Clorox wipes are the ideal tool for that.
2) Soak the whole thing in a 1:1:1 solution of Alcohol:Water:Bleach for about 20min. That should kill any germs on it.
If you're wondering why I'm including the scales, it's b/c some more resillient viruses may hide b/w the scales and get transferred onto the blade. The chances are microscopic (pun intended) but it's better to be safe than sorry.
Bleach may be aggressive on some finishes, but in a salon where a friend of mine works, they make a special point of not using Barbiside on metal implements. Look into using clippercide though.