Something new for those who want to remove colour, as in play with fabric. I found this explanation and couldn't say it better.
This citrus paste/creme is available in an 8 oz. jar to stamp, stencil or print with. There is a 4 oz. spray bottle available too. deColourant is safe to work with and does not damage your fabrics. It requires heat to work , either ironing, a heat gun, or even the sun! This product is a pretty safe chemical, but as always you are encouraged practise proper use and safe working conditions. They tested this product on hand-dyed cotton, silk and wool yardage and found it to discharge well, in addition to showing no damage to the fabric.
As always, you should play with it first to get to understand the qualities, quirks and possible uses in your work.