I ended up trying the wash on three modules two Pulsars and one NSC. I gave the modules 4 dips -
1. Vinegar.
2. Bicarbonate of soda (I thought this would neutralize the acid, it did give a lovely fizz

.)
3. Distilled water.
4. Isopropanol.
Results.
It made no difference with the Pulsar modules, maybe due to the black paint covering the board? so these have been sent off to try with oscillators.
The NSC has definitely improved, it needed heating up to fire it up initially but it has been working on its own for a couple of days so I will have to wait and see what happens long term.