Ty for your replies guys, my supplier at centurywise is back from holiday now so problem solved.
We did call in to travis perkins but the brick cleaners and paint removers that they have are not heavy duty enought for the type of work that we do.
Our company cleans building exteriors with pressure washers and chemicals, we require industrial strength chemicals to do the job effectivly, the stuff you get at most builders merchants or diy stores just is not strong enought.
Yes if used incorectly the acid or pressure washer can take of the face of the brick and do serious damage to the users health this is why the chemicals that we used are not available for the general public. The hydro fluoric acid can even etch windows.
If you are interested in finding out more about this kind of work and the techniques used you can find most of the information at the link in my first post.