It will come off with a wet cloth on most surfaces. Of course, you will want to experiment with a few surfaces first and check for visibility. G performs it on a dark table and a wooden table on the trailer. The surface needs to be fairly hard, it probably won't work well on a piece of upholstered furniture, but it could possibly work on a table with a table cloth. The writing should come out in the wash.
There are a ton of ideas covered though. A few handlings without a table as well as a few handlings that use the method as a peek device. In some, the name travels from one card to another, in another effect taught you use G's method to perform ashes on the palm without the need of ashes.
