off of this...
(since this doesn't phase him in the least)
I went in search of a better way. I tried many things, including these... (all shamelessly pillaged from Gloria's box of musical instruments that we have accumulated over the years)
Sadly, none of them worked. The most response I got was a squinty, blinky look and maybe a backward turn of the head (which was probably really a stretch or something and not really a reaction to my noises.)
Then I tried this...
and it worked! Last night, he was only on the table three times while I was working. After the third obnoxious round of quacking, he gave up! This afternoon, again, only three quacks. Actually, by the third time, I don't really even have to quack. The sight of the orange beak makes him run. We would go round after round after round of water bottle squirting after which he would literally be dripping water in puddles and he would simply look at me like "Do you really think a stream of cold water REALLY bothers me? You poor two-legged creature. You really don't know a thing about me do, you?" But the QUACKER?!?!? He appears to hate it. His ears go flat, his eyes squint up, his body curves into that defensive "c" shape, and he TAKES OFF.
Run, Screamer, run! Stay off my table, you bad cat! Make us happy!