That's what I do, and it works fabulously! Just sound excited, say "Oh, can you hang on a sec?" and put the phone down on the table without hanging up. I've even managed to come back more than 10 minutes later, say "Are you still there?" and get a "Yes" response! I then just said, "OK, great, can you hold on for just another minute?" and I put the phone down again and went back to cooking or whatever. After a while, he hung up. Poor sod. NOT!
(It helps that both my wife and I have difficult last names to pronounce, so when we get calls asking for some incorrect pronunciation, we know it's someone who doesn't know us. And in case you're wondering, we're in Canada, where people can keep their original last names when they get married.)