"Whilst I wouldn't want to use this to rake out modern cement mortar (I think it would be very hard work) I have found it fine for use on old, soft lime mortar, which is what I bought it for,
If you're not sure (and I was considering getting an angle grinder) try raking a bit of your mortar with an old nail or similar. If it crumbles easily then this is going to work just fine and wont risk damage to your bricks."
"It works fine but you left with a indented thumb as the clamp to hold the nail simply doesn't work. Nail dropped out after raking for a total of 20 seconds. So if you want recessed pointing it's to the full depth of the nail your using You could just get some hardened nail to the depth you want. Other than that it's fine."