Done that, no luck. Also made and scanned some of that tainted cloth, I don't know of any other tainted items in the pack.
Well, tainted nodes, crusted taint, the purple tainted soil (not the natura stuff), as well as fibrous taint - the difficulty with all these naturally being that you can't actually get any of them without a tainted biome unless you use a primal charm which I am told has a small chance to produce fibrous taint. You might try using the camera from Witching Gadgets to get another scan of a flux slime. I don't know if it works for blocks or items, though.
I tried to taint a biome by dumping stacks and stacks of flint into a crucible but despite a flux puddle nine blocks across nothing happened except a bunch of flux slimes spawning.