Stop buying PH Buffer solution

Trying to save money (as always) I looked into making my own Solution...
Well, that's not EASY!! - I like easy and cheap. What you will see in this video is how I preserved the PH buffer solution that came with the PH meter.
I figured I'd give it a try - worst thing, it does not work.
Just in case, I purchased more buffer solution - you never know when you may need to recalibrate, right?
You will see the 6.86 solution only got to 6.77 - I had a feeling this would not read correctly when I first preserved it, as I stirred another solution just prior and did NOT rinse off the spoon.
However - If you test one of the preserved solutions at a time - let the PH meter dry out between the different solutions, you will not introduce fresh water to your preserved solution, nor will you risk shaking droplets into the solution and therefor you could preserve them even longer.