From what I've read, there aren't any whales (with the possible exception of orcas, which of course are dolphins) that have a gullet wide enough to fit down something even close to human-sized. A whale might try to swallow someone out of simple ignorance, but they'd quickly choke and spit everything in their mouths up, including the unlucky swimmer!

Good thing, too. Whales, even baleen whales, have a two chambered stomach rather like a bird, and one of 'em is a grinding chamber. That would ruin your whole day.