L Art Du Son really does what it claims, and i wouldn't exchange it for anything else. Yes, it has a best before date and you need to be really clinical when mixing, storing and handling the stuff.
It's life, but not as we know it!
I gave a bottle of premixed to my friend to try on his Okki, but i was cheap and used a used bottle (used for and old mixture of cleaning fluid, so nuttin worse)
Within two months some form of mold had grown in his solution and it was useless.
However, i o this doesn't have any bearing as the records are cleaned and dried and my opinion is that nothing will grow, or even stay on the surface after the cleaning.

For me, cleaning also removes any static build up and i think youre overusing the vaccum Marco!

Best regards Mike