removing heavy paint off brick?

[dunicraig]

I have a space where I want natural looking brick however over the past 100 years or so people have put layers of paint over the brick to keep moister out and/or to brighten up the rooms after the factory was gone. There is very heavy build up of paint on the brick so thick in some areas it looks like theres not brick at all just a wall. The past day I had my son sand blasting these 14 foot walls however it was some what of a slow process because it was not really taking all the paint off. Is there such thing as courser sand or will that just clog the nozzle or is there a better way to remove the paint? By the way its old paint very old alot of lead so I dont think paint remover will work I tried I on my floor in my very old house it just got rid of the laytex paint and did nothing to the lead. Any other ideas?