Whitewash/limewash same thing. Distemper includes linseed oil I think.

You can make whitewash from a bag of builders lime (£5/bag and one bag
will last the rest of your life) - mix with water in a plastic dustbin
and leave as long as possible (days/months/years) - this will give you
lime putty at the bottom, with excess water on top. When needed, swirl
it up and scoop off some of the whitewash. Coats should be painted on
so thinly to be semi-transparent when wet. Build up lots of coats.