....little thingy ...on end of a fuzzy stick .....geez man ...( there may be a few technical words you've left out ..) ....
Intentionally cross-contaminating powder...

...really ....???
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To make a cheap sieve ....get a plastic funnel ...and cut it off, so it has about a 5" opening ...and go to a hardwear store, get some fine mesh window screen ... and staple it to the outside of the funnel...and you have a cheap sieve or strainer...that will take the shot out of the powder bottle. If you don't want to use a funnel ...you can do the same thing with a large tin can ...( for tomatoes or something ) ....
Maybe you should consider --- straining your powder cannister of shot ...before every reloading session / just kind of like taking a minute to "screw your brain in " ...so to speak ....( which I mean respectfully, my friend ..) ....
or maybe invest in a decent reloader...like a MEC Grabber model ...( we know you're frugal ....but just saying .../ maybe the Sizemaster...has seen its best days in the rear view mirror...