I have used RIT both successfully and very Unsuccessfully. I won't use it anymore unless I am wanting to create gradients in places that I know I won't be painting like legs, ears, nose and only if I feel that the colours will fade nicely. I have had a couple of my customs look absolutely terrible after a couple of years due to fading and bleeding. Lemme see if I can find any pics of the specific one I am thinking of...
Okay, well I give That search up! XD Anyways, I don't recommend using RIT to dye. If you are only worried about brushstrokes I would recommend using a sponge technique to do a smooth FBR; I used this technique for these ponies and they turned out quite nicely,
Anyways, hope that was helpful, if not quite what you were looking for. :P