Solvistrip and Peelaway won’t touch limewash at all, but they may get you back to bare limewash. I tried both at some point. In my case the top layer was a crappy plastic masonry paint - complete unsuitable for a solid brick wall, stopping it breathing properly. However, plastic masonry paint does not adhere well (it least in this case, but i also read that generally it is true) so a lot of it was peeling and flaking off. To remove the majority of the rest i used a pressure washer. In a few places it had adhered quite well, in those areas i used some generic cheap paint stripper gloop (just benzyl alchohol gel) which works but creates a sticky mess. It was not a pleasant task, and often resorted to holding hose jet in one hand and a brush attachment in a cordless drill in the other to basicalkt brush it off. This was all done on the basis that no mineral paint was gonna stick to plastic paint. i had tried some ither ootions like a paint removal disc in an angle grinder but it would dig into the brick easier than the limewash and so left some marks. I also tried a hot air gun and a scraper, that also ‘sort of’ works. ‘Aciclean’ is just hydrochloric as far as i could tell, like any ‘brick cleaner’, just the strength varies, anything up to 20%. They worked in some areas more than others.
If you have a lot of masonry paint to remove consider getting a contractor with a thermal/steam solution like a Jos? to blow off that layer then you’ll be good to go with the mineral paint. Keim is brutally expensive - gotta be at least £500 on that wall. The reason i went with it was that they had good test data to back it up (moisture absorption and evaporation), i was less impressed with the info from Mike Wye regarding Ceciltek Silicate paint - a blurry crop of a tabulated data with no reference to the product name.... i’m sure it’s a decent product but was fed up with researching by that point....
i got it back to looking like this:
Closer finished result: