Alright bro, well the 2 areas which you covered are Perfect.. mainly ECU and Generator are the areas which need to be covered.
Here are few pointers for you:
- Do not put continuous water on sensors, there are 3,4 sensors total.
- Do not use Petrol or Diesel as it will attract more dust later on.
Steps:
- Rinse the engine with Tap water, use normal water pressure.
- Better make some mixture of Shampoo and Water, or Surf Excel and water.. and spray on the engine.
- Use different brushes, like tooth brushes and some long handle brush to cover the deep areas and remove the dirt.
- Again wash/rinse the engine with water and remove the dirt and shampoo.
- Dry the engine with some cloth, cotton cloth or Microfiber cloth
- Do not start the engine if there is water on sensors, use air-blower to remove drops of water on engine.. so make sure that your engine is water free, without any drops.
I washed engine bay last week, here is the video recorded. i didn't cover the Generator motor and also the Brush/rubbing part is missing in this video as camera was on Pause.
<iframe width="640" height="360" src="http://www.youtube.com/embed/4-zUkPqilkE" frameborder="0" allowfullscreen></iframe>
The bottle i used is easily available on hardware stores for Rs.250-300 or go Hyperstar you will find there. Also the mixture inside that bottle is 1 part of Turtle Wax Pre-soak and 5 parts of Water. That Pre-soak is available at SACA plus shop Mintgomry road for Rs. 500 (half liter). I recommend this but even some shampoo can do the job 
All the best and do post Before and After Pictures Goodluck
