I'm not sure what would make us want a tougher option with broader effects on microbes. The alcohol already meets the bar in drug manufacturing, so that works fine here too.
I'm wondering whether folks are employing a phenol and water mixture when mixing up their stuff. It's said to offer more potent and wider-ranging protection. Maybe combining phenol with the usual benzyl alcohol? That's apparently how insulin manages to stay good past the standard month. I'm open to chatting about the reasons behind different approaches, though I'm not aiming to alter what others do. No intent to question anyone's methods here. I've got personal motivations for wanting to lower my own potential issues, so this isn't a critique of alternative choices. Technique chats are welcome though. And for those incorporating phenol, any suggestions would be great to hear.