This results in tiny bubbles, as in carbonated drinks. This bubbles can be an extremely strong force, physically lifting and breaking apart weak fibers. In the same manner, it is sometimes minimally effective on foxing stains, physically lifting the rust spots off the surface of the textile. The borohydrides can also be used in alcohol. There are several advantages.
Alcohol tends to swell fibers less, resulting in less mechanical damage.
The borohydrides react slower in alcohol, and do not emit as many bubbles of hydrogen gas. The use of this bleach is fairly new in the textile conservation field. Research is still being carried out. These substances are difficult to rinse out of the fibers. Residues will continue to bleach the textile for awhile, then will reverse, bringing stains back up.