Two Things:
1. RIT dye is a salt and, even after drying, has been reported to conduct current between the rails. This is probably why we have not heard of it very often in recent years.
2. On a TV show about real trains, I saw an UP trackman say that uniformity is good. Ties that are old and weathered pose a potential problem. Uniform dark brown ties are prototypical, especially for mainlines.
Ed
