When using isopropanol (rubbing alcohol) for sanitizing, 70% is the better choice than the higher %, because the 70% does not evaporate as quickly, thus the alcohol remains in contact on the surface longer, giving it more time to work.
It denatures proteins, which is the aim with bacteria, fungi & viruses. But as
lenarenee mentions, spores are better protected by their outer coating, so it may not penetrate.
When I taught CPR, we soaked all re-usable parts that came into contact with people (mouth-pieces, etc.) in a 10% bleach solution for 10 minutes per the CDC guidelines in place at that time, so l
enarenee's use of bleach makes perfect sense. But so does alcohol on un-used brand new bottles for cosmetics. I also like the idea of sanitizing wand
SunRiseArts uses, but haven't read up on that method.
In the US, the FDA has these
guidelines in place, as well as
this, but they are certainly vague on the topic of container sensitization. I suspect there are more explicit regulations in California and Florida, as well as in the EU, but I really don't know.
For further information, here is what the CDC (Centers for Disease Control in the US) recommends for in-home disinfection of re-usable medical-related items:
11.b. When performing care in the home, clean and disinfect reusable objects that touch mucous membranes (e.g., tracheostomy tubes) by immersing these objects in a 1:50 dilution of 5.25%-6.15% sodium hypochlorite (household bleach) (3 minutes), 70% isopropyl alcohol (5 minutes), or 3% hydrogen peroxide (30 minutes) because the home environment is, in most instances, safer than either hospital or ambulatory care settings because person-to-person transmission is less likely.
Granted that last one is a quoted from their guidelines for Healthcare, which is more strict than the US for cosmetics.
https://www.cdc.gov/infectioncontrol/pdf/guidelines/disinfection-guidelines.pdf