The SSSCAT Cat Training Aid works great.
When we moved the tank back into the house and before water was added, our cat was going to re-investigate. I am guessing he noticed no can od SSSCAT, so jumped up. He also learned no lids. I haven't seen him go near the tank since. lol
All three of my trouble cats had splash down experiences in my 20L, some more than one. They still went right back at it the next day