Soak? Why would you consider giving your CPU a bath in alcohol? No, in my book, that is entered as a bad idea.
Not the worst idea mind you, if you were to have a need to do so. I can't think of any offhand. You would then need to soak it in distilled water for about 10 minutes, followed by rinsing well with a bit of distilled water, followed by soaking about 15 minutes (with agitation) in distilled water. Finally, drying it for about 48 hours or more depending upon you humidity and heat - it can be done.
Still not advising it.