Or drill it out by hand and flush with fluid. Don't open the system yet, the pressure will help blast the debris from the hole.
The size isn't that specific but leave it very small. A complete jewelers hand screwdriver kit is less than $5 on e-bay and handy for all sorts of things like dirt bike jets... or carb jets on a POS El Camino that swallows rain through a hole in the hood you cut out just because you wanted to put a huge scoop on a old tired small block and now it's your daily because you took your van apart, again.
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Oops, I was digressing.
But a YES to the Oberon. It's pricy, but dang worth it 100%.