instead of using a household item, why not build a project from stratch to look like a household item?
for example, you ever see the flying lawnmower?
http://www.rc-airplane-world.com/flying-lawn-mower.html
check out the flying things on this page.
i like the stop sign, flag, and the snoopy dog house.
http://www.rc-airplane-world.com/flying-lawn-mower.html
a large anvil would be cool.
if your intent on using an exsisting product, why not try and find a battery powered "power wheels" jeep at a garage sale. throw a small child into the jeep (a fake small child) and drive it into the pond.
should be good for both shock factor and fun.