Yes, washing these types of aluminum apple keyboards with water will usually resolve the problem, just pure water, and a few days of drying… it doesn’t make sense, but I have fixed a dozen of these that way before! It’s no guarantee, but it could resolve it. The reason the keys went out together is that the buttons’ are organized into columns and rows electronically. When the circuit is connected on the sixth column and the second row, that equals a 5 key. Sixth column third row would be the T key, etc. So your problem is not at the keys, but with the column contacts for those two columns. Whether cleaning them will help is anyones guess. Somehow, you have a break in the circuit for those two columns of the keyboard. It sounds like the problem will be on the logic board of the keyboard. Check for hairs or something shorting out any chips, etc.