The blade isn't much of a problem. If it is dry, then most bacteria will only be able to live on it for a few minutes, some for a few hours, remarkably few for even a few days. The part near the pivot isn't much of an issue either - brass self-sanitises in 24-48 hours, killing most things living near it. What bacteria really like are soft, wet surfaces with a food source. Ever taken an old razor apart? It is not uncommon to find a matted mess of bristles, soap scum and other residue - really filthy in some instances. I guess that could hold water for quite a while.
As long as the scales are clean inside and out (don't immerse them in alcohol or any type of solvent - some scales will melt, others will develop a 'frosted' look) and the blade is aired and dry, you shouldn't have a problem. Just leaving it open in an airy place where direct (ie UV) sunlight can get to it will keep it safe.
One interesting study about the use of alcohol showed that up to a point, increasing the amount of alcohol to water had no beneficial effects - in fact, a certain amount of water makes it a more effective germ-buster. Iso-propyl alcohol should be perfect.
Regards,
Neil