With this thread in mind, I decided to properly clean a spare, very yellowed ADB Extended keyboard.

Once the phillips screw at the back is taken out, it comes apart quite easily.

I suspect that this keyboard has never been cleaned and it is surely 25 years old.

I took the keys off carefully with a penknife and put them in a cloth bag into the washing machine.

The upper and lower case went into the dishwasher.

The logic board and black rubber underlay to the keys I cleaned initially with a hoover and then with many cotton swabs dipped in disinfectant alcohol.

I'll see how tonight if it was a success.