A lot of people speculated in second home buying and leveraged it with the equity in their own home.
That would be a candle burning on both ends IMO.
Anyone doing that really needs to have everything go right.
There do seem to be a lot of get-rich-quick real estate seminars out there that want to teach you how to do stuff like that. I always figured if it really worked, and they knew how to do it, they'd have done it, and become too rich to need put on seminars :)