I haven't acid washed brick, but I have fauxed brick and it's cheap, fast, and easy. I have pictures in my fireplace thread that's (right this minute) right under this thread if you care to look. Basically, you can put two or more paint colors on one damp sponge at the same time, and pat them all over your brick to change the color/looks of the brick. If you use acrylics (I get mine at Michael's) they are less than $2 per bottle. Or, you can use latex paint.

I don't have experience...yet. We took the stucco off of our chimney (exterior of the house) and we have considered using some kind of acid to clean the remaining stucco/concrete residue off the bricks. The brick in our case is about 100 years old and fairly soft, so it's not something we want to rush in to until we're absolutely sure it won't damage the bricks. We are considering phosphoric or muriatic acid, and I'm assuming that's what your supply guy was referring to. As you can imagine, acids can be very dangerous to handle, especially if it needs to be diluted with water as it no doubt will in our case. Make sure you find out how to deal with it safely should you decide to do some kind of acid washing on your brick.

Yes my husband did it.You use muratic acid I think its called.You dip a brush in it and scrub the brick.It will be messy .Rinse when done.