What to do with crumbly brick on old house

I'm tired an

d achy so I'm going to make this short. I live in a circa 1870s house. I bought a circa 1870s house to rent. I bought it at auction, after it had been auctioned before. I went through 1.5 contractors and am now doing the finishing touches myself, sans contractors. And that is why I am sore and achy. 

But you want to know what to do with crumby brick walls. The first person who won the auction started demo prior to closing on the house. I do wonder why he didn't finish the deal. One person suspects sewage. I suspect the butt ugly crumbly wall played a part. 

In the bedroom he exposed (I know this because I remember what the house looked like during the 1st auction) the brick walls. One was pretty, the other, not so much. Actually it was downright ugly with sandy-sandy mortar and uneven bricks.

This was not a problem for me. I had the same sort of bricks in my home. Here's the solution, either parge it and cover it up with some insulation and drywall, OR cover it with thick paint. Not just spray paint on the wall, no. You got to coat it like you're a furrier and it is Zsa Zsa Gabor. In the photo above, that looks like it is on its side, I am covering the contractor's work, adding the 3rd coat of paint that was needed. You need a rough surfaces roller and you have to squeeze as much paint into the craggy bits.

I've had my painted brick wall for well over 10 years. Yes, it occasionally bleeds red brick dust, but nothing a little patching can't handle.