The only way I know to keep them off furniture is to crate them or otherwise confine them when you are gone. My dogs pretty much sleep wherever they want in the house when we are home, but are always crated when we are gone. You can crate train older dogs. My last dog that wasn't crate trained as a pup was 15 and had back problems and needed to be confined. It took a couple nights of fussing, but I crate trained him at 15. After that, he loved his crate and would go in there to take his naps.