I've done a Gottlieb motor board the same as they do the bingo in that video. It didn't come to any harm. I blew the water off thoroughly with an airline, paying particular attention to blowing it from inside the loom, and left it to dry for two days. When I fired the game up, there was no problem. Obviously, any lubed metal to metal joints need new lube. It does give nice, clean components but I'd only recommend doing it if you intend to go through everything after cleaning.
The cleaning did an excellent job on the ply board, components, switches etc. but I wouldn't say it made a big difference to the wiring. It did brighten it a bit, but I think the problem is, it's not real easy to get the dirt out of the cloth insulation and any colour fading can't be altered.
I'm in the UK so used a different cleaner than the blue stuff the Dutch guys used on the bingo. Obviously, all the labels on the motor board have to be removed. The cleaner I used took all the black letter or number ink off the labels actually fixed to each relay and the score motor. Either new ones need making or letters / numbers added to the white labels with a felt tip pen. It also loosened the glue joints on the paper coil wrappers and some came off when I used the airline. They dried out OK and I refitted them. The coil wrappers on bingo games are much tougher, some kind of black insulating wrapping, a bit like the black wrapping on some Gottlieb coils. The cleaner and water doesn't seem to bother that wrap but it does affect the paper wrap.
I've also got a bingo which was cleaned as per the video and the wiring in that is still all faded and mostly the same brownish colour.
So I would conclude: if you want to clean the components, it's worth giving them a good wash & brush up, as long as you have an air blower to remove all the water and intend to go through everything after you've cleaned it. If your only trying to clean the wiring, I don't think it really does a good enough job to make it worthwhile.

Nice game mate, should be a great bingo to play. I reckon they always got filthy, they were, at least over here, always in greasy spoon cafes, and everybody smoked.
When I first saw the Dutch guys video, I thought, no way. I watched it a few times and, every time, it stunned me the way they soaked literally everything, wood, electrics, motors, transformers, steppers, relays. I thought, that's got to cause damage of some kind. But I have a County Fair they restored 4 years ago and it works like a dream. I was going through a Sing Along with a dirty motor board, so I thought, lets try it. The result was: no damage and a lovely clean board. All the switches and relay ladders look near new. As I said, it didn't clean the wiring that well but I'm sure your game will smell like a flower garden if you use the right cleaner. I used an all purpose kitchen cleaner recommended by a fellow bingo nut.
I, and I'm sure others, would love to see a few pic's as you restore your game. All that tumbled metal will be a lovely sight. Post us some pic's, and let us know how the looms come up. You might hit on a brilliant method we could all use.

Here you go mate, be amazed:

The wood in those old bingo games is mostly covered in a film of oil and crap anyway, I doubt much actually soaks in. The water, in any quantity, is only there for a short while. It's quickly blown away with an airline, leaving little to air dry.
If the cabinet joints are bad enough for that to open them up, they need re gluing anyway.
I have a game that went through that exact process four years ago, it is still absolutely fine in every respect, no loose joints, no corrosion, looks and plays as good as new.
And, bear in mind, that cleaning is the initial stage of the restoration. After all has dried out, the game is restored top to bottom. Any loose joints are re glued and clamped, everything is dismantled, contacts cleaned & adjusted, steppers stripped & rebuilt, control and mixer units stripped & rebuilt, cabinets re painted. When they've finished, those games are near new. These guys are passionate about old bingo games, they don't do a quick flick job and sell them on.
See here:
http://coos.net/bingo_e/