|Try Tecnu. I read another sufferer's reply in another post. Sounds like a lot of people use and trust this stuff and it says it can remove the oil from clothing, etc. (Of course...test a small, hidden piece of furniture before you try it on the large pieces.)
Here is a bit from the tecnu website.
"Urushiol oil can also spread from contaminated clothing, shoes, gloves, tools and pets. Since the oil does not evaporate, it can remain on these items for months or even years at a time. Use Tecnu to remove the oil and avoid a rash from secondary contact."