Now. After soaking some Three Hundred Blackout brass for three hours, with intermittent agitation, in just Lemi-shine, I am looking at clean, somewhat shiny brass. Frostier looking than tumbled and much less shiny than pin tumbled.
With some patience I could talk myself into using these. But, no. The pockets are untouched. They don't look as caked on as my pistol brass, but I will have to seat primers in them to see if they will allow me to seat them all the way flush. Without squishing an indent into the primer. (Though that only happened with well used brass and this is single use. I anticipate no problems. )
And nope. Couldn't do it. I dumped the cases out onto my bench to put them in their new bucket home. With the brass gone I was left with black crumbles of smeary primer residue. I enjoy a nearly surgically clean handloading experience. These smudges will not do.
Maybe more of the loose filth would have been removed had they been tumbled. Pins or not.
I will revisit making a new container. (Again.
Nearly indestructible and worthless for any other purpose. I have four already...) This time with much smaller baffles.