I finished up with my tank tonite. I washed it out at the carwash, put in some rubbing alcohol to disipate the water and blew the inside dry. Anywhere I can see inside looks perfect. I'd say it's perfectly usable as is but I'm still gonna coat it.
The real test will be my other tank. The tank I did was off my parts bike. It's gonna stay stock. The tank off my bike is bad rusty, like plug the petcock rusty. It's the tank I'm gonna modify. I plan on using electrolysis to clean it and then cut it apart. I'll know then how clean it really is.