Vintage Double Hose

I have used previously a whip/brush, loaned to me be a friend at the LDS, to scrub the inside of tanks of flash rust. Sadly the LDS is going out of business and I figure I might as well get one. I just got my 38's back from hydro, and while the guy doing the tests said there was no problem - no pitting, I should clean the flash rusting. Can someone point me to a good source?

Thanks
Geoff

http://www.gmcscuba.com/

I am a Global dealer and use their products for cylinder maintenance and O2 cleaning.