We shoot "Cold gun".
its up to your own knowledge of you given firearm to know how it performs clean or dirty.
Granted, we have people who, shall we say, cheat or bend the rules,and when I say "we" I am refering to everyone abound.
I feel it is part of the "complete package" to know what my gun will do under various conditions...clean, dirty, 40 grs, 65 grains powder, tight patch, loose patch, thislube, that lube ect.
I feel if its allowed, fine...If its not and is public knowledge for a particular range or club, okay then, BUT allow outsiders the same knowledge.
Personally, I dont take a "sighter" or "Fouling shot", IF I needed to, I could touch them off at home prior to driving out to wherewe do "our" thing, and no one would be the wiser.
sorry if I kicked the beehive,
Brett