Who has cavity wall insulation removed? The effect on your heating bill is going to be much worse than a small amount of mould, and I'm unconvinced that it makes it worse anyway - one of the main causes of mould in my experience is poor insulation! It makes the walls cold, which means you get condensation on them, and if you have poor ventilation in the rooms then you get mould.

If you have this problem, then the only thing I found which helps is fungicidal wash, and keeping furniture away from the problem walls (especially north facing corners of the house). I suspect wallpaper would also help but I never tried it.