some walls need to be hacked and re-erect new brick walls because inside is too moist. if the issue prolong for a few years definitely there will be no cure.

solution to this is hack and rebuilt. don't waste money on waterproofing products.

some old house more than 30 yrs, 40 yrs are not worth doing major renovation. better to sell it off and purchase a new house.

Cannot fix cos myself experience a few walls in different projects before.