Does raising speaker cables off the floor really make a big difference?

Absolutely not. It is just a way of showing off your over priced cables. The best way to deal with speaker wires is put your balanced mono amp right behind the speaker keeping your speaker wire as short as possible then run long balanced cables to the amps. If you want to put them on cable elevators knock yourself out.
Geoffkait go to Wikipedia and read about static electricity. Then look up triboelectric series. But, you are right. Cable elevators can not fix static electricity nor can they fix anything else other than the finances of people selling them. I would never buy anything from a store or web site selling cable elevators or any other patently obvious BS.

More audio hocus pocus.

prof
Never heard a difference.

>>>No surprise there. You must be the unluckiest guy in the whole world. 

I do not believe it makes a difference. Just expectation bias. 

But my cousin swears by them.

He has tested quite a few different types. He likes those porcelain ceramic insulators. They can be found for a lot less money than the ones made for audio.

Just google ' porcelain ceramic insulators' and you'll see what I am referring to.