I am about to retuckpoint my exposed brick wall with a custom mortar mix (1x hydraulic lime, 2.5x sand). Once I am done, I plan to clean the residue and other dirt from the bricks using muriatic acid. My question is: what is the minimum amount of time I should wait for the mortar to cure...

So i just built a brick hearth in my living room. Apparently I'm not very good at buttering bricks, because despite my best efforts when laying it, the bricks look mostly grey from the mortar. Will Muriatic Acid fix that?