I think you introduced them too soon.

When I brought Cole home, he had his own box and everything in the bathroom, and I kept the door closed. You can use a cut-down cardboard box as a temporary litter box. Use the bathroom, or a separate room.

Let the kitties get used to sniffing each other under the door, and maybe playing "pawsies".

Remember, this is new for both kitties.

Just a thought...instead of putting water on the cat's neck, how about just putting water in your hand and flicking it at the cat? I think by the time you get the cat to the sink, they've lost the connection as to why they are there.

Keep them separate for several days yet, and bar all 'accidental' meetings. And when they do meet in person, let them loose but supervise them. When they were held, they probably felt trapped as if they couldn't get away from the other cat. They have to sniff and swat things out on their own.

Sorry to be so long about this...

Catty1