You are probably cleaning the inside of your powder measure too much.
Through use, a layer of graphite from the powder will build up n the inside walls of the powder measure. This, among other things, helps reduce the static. Aggressively clening the inside of the measure removes this layer and you will have to rebuild the graphite layer again.
As a side note, Lee Precision recommends running a pound or two of powder through their powder measures to "season" the internals before loading any ammunition with it.
When I am finished using a powder measure, I dump the hopper back into the original container it came from. Then put the drop tube end in the container and rapidly cycle the powder measure from stop to stop to drop any remaining flakes of powder into the storage container. Sometimes, if the powder measure has a bit of static, I have a long handle artist's brush that I can reach down into the hopper and sweep the remaining flakes of powder down to the metering area and out of the powder.
With a new powder measure, I sometimes store an anti-static dryer sheet in the hopper when the powder measure is not in use but over time and use, that becomes unnecessary.
In 40 years of reloading, I have never cleaned the inside of my powder measures.