I'm sure I read results of some tests somewhere that showed alcohol was less effective against some virii than the physical washing process with soap for example on your hands. I think it showed it was better against bacteria.
I guess you could always use uvc but then you'd have the problem working out the exposure needed as it varies considerably iirc depending on your likely pathogen. Then again some handle materials might not like that either.

I think many of the previously mentioned methods like bleach or barbicide wouldn't do too much harm if only used when you buy a new used razor. I mean if your the only person using a razor you aren't very likely to catch something from yourself.