There is so much mis-information circulated everywhere about Silicone Brake Fluid (SBF) we wonder how anyone sorts it out.
Whatever the problems with SBF, and I am not sure there are any, the problems with using the more common glycol fluids are potentially much worse primarily because of its ‘hygroscopicity'. Remember not to confuse glycol fluids with the very different Mineral (LHM) Fluids which are used in many Citroen and Rolls Royce vehicles.
NB A given volume of glycol fluid will absorb a given volume of moisture in a given length of time - nothing can practically be done to prevent that! The moisture will even penetrate through the seams of a sealed container, even when it is in a tin!
In effect it's losing it's grade from the moment it is made. The manufacturers know this, which is why they specify regular bi-annual fluid changes.
So what are your options?
Give up the car and take a bike.
Buy fluid from a good source where stock moves quickly and gets rotated.
Test the condition of the fluid regularly.
Buy "new" and keep doing it.
Properly drain and bleed the system with DOT5 Silicone Fluid and then forget it, except for topping up. SBF starts off purple so it can be identified easily.