Sounds like you are applying too much pressure with your applicator (Q-tip), you only want a very very light touch. LMF browning solution is pretty worry free, after about three coats any of those dark spots and coppery stuff will disappear to be replaced by brown, it takes that for things to even out. Do put the parts in a humid environment, it does not take much humidity. Don't go too quick with the browning, control it, it should take somewhere around 5-6 hours between coats, do card after each browning session (remove the reddish stuff). You should be done after about 6-7 coats. To stop the process I heat the metal a bit (not too hot) and apply oil liberally.
dave