I've never shot Tula, but I have handled a fairly large number of fired Tula brass cases and did not find them to be particularly dirty.
If you're talking steel case stuff, I can't say, but I would be surprised if they were loading the steel case much differently than the brass cases.
The once-fired cases that present the greatest challenge to me when trying to clean them are ones with headstamps Hornady, PS, PPU, Perfecta, WCC, WMA and Wolf. I take it that this means they are "dirtier" than other headstamps, but nothing strikes me a "filthy". It could just be that these dirty cases end up laying out on the range longer than others before being picked up, but since my "sample" of once-fired cases numbers many thousands and comes from multiple sellers, I tend to believe that variable is effectively controlled for.
I have bought 60 rounds of .223 Remington in my lifetime and still have 37 of them. Other than these, I load all of my own .223, so the only basis I have to judge is from the fired cases.