My daughter had a "tomato sauce explosion" in the immediate vicinity of her keyboard a while back.
It is a membrane keyboard, but as far as membrane keyboards go it is a pretty nice one. Even after I don't know how many years it is still as crisp as.
It is a Digital RT3356T winkeyless keyboard in two tone beige.
I spent the last couple of hours disassembling it and cleaning it.
The plate had a layer of dried tomato sauce in the lower left corner, the keycaps had all sorts of gunk over them, and there was a thick layer of dust and hairs between the keys.
I didn't bother going quite as far as disassembling the membrane, as the keyboard basically worked (apart from quite a few gummy keys).
But the keycaps were cleaned in denture tablets and then scrubbed with a nail brush, the case upper was scrubbed with a scourer in the kitchen sink, and it has come up pretty clean.
The various parts are still drying - to be reassembled some time next week.