Jetwash before painting over masonry "paint"

[Tangowagon]

Hi guys, my latest renovation project is built from solid 9" Victorian brick that has been painted with brick red masonry paint, though it is quite thick and flexible where it is peeling off and I suspect it may be a "coating" rather than masonry paint (is there a difference?)
As I say, it is peeling in places & needs some attention before I re paint it. I have had a company do a test area for grit blasting to remove it all but there is a green paint underneath that could be oil based & the bricks & mortar were being badly eroded by the blasting before all the green was being removed so it looks like I'm stuck with painting over it but how to remove the flaky bits? Spending a week with a scraper & wire brush is one soul destroying answer, has anyone used a jetwasher? I'm thinking hire a 200bar professional machine, hot or cold?
I know that I will probably lose some mortar but repointing is not a problem, if I do it soon enough, there will be enough of summer left for it to dry out before re painting.

 

[Bonni]

You should never render, paint or use cement on a solid wall. You just trap damp in.

 

[Tangowagon]

You should never render, paint or use cement on a solid wall. You just trap damp in.

Yes, I know that, but the damage is already done, ideally I would sandblast the whole building back to bare brick but as I said, this is not feasible.