This wasn't taught. She's a F1 bengal, which means she has roughly 56.25% Asian Leopard Cat blood, so naturally some instinctive behaviors are exhibited.
Asian Leopard Cats often urinate and deficate in water. It helps to mask their scent from predators, allowing them to remain very inconspicuous.
Bakula has no rivers or streams to eliminate in, so she makes due with the toilet on occasion. She uses the litterbox as well.
So no training and no coaxing, she does this just because she feels like it's the right thing to do. It's a very cool thing, but I think if a sink was left full of water long enough, she would probably think that was a good place to go as well. Filial cats such as Bakula, need informed understanding owners that can accept their quirks as perfectly normal behavior.
By the way, and I've mentioned this before, but it's worth repeating, Bakula is not my cat. She belongs to a very close friend, so we are updated weekly, and we love her as our own. She is very special.
Bakula will be mated soon to one of 2 boys from our cattery and we will get some F2 girls to add to our program, or maybe just as family members.
It's a very exciting time!