Many options exist.
1. Vacuum cleaner blowing in a low setting onto the computer box placed in a corner on the terrace/balcony.
2. Electronics cleaning putty.
3. Dismantle and clean (this may rule out some parts due to the warranty stickers etc, and also because some times it is not easy for everyone to separate the electronic/electrical parts from the others since many of them are glued in place by the maker etc.)
i. The electronic parts in IPA with lint free cloth or cotton.
ii. Plastic parts in soap or detergent solution, or Vanish/Easy Off Bang. I didn't use Harpic because it has 10% HCl.
iii. Metal parts similar to plastic parts but dry them immediately in Sun.
Since the method 3 takes a lot of time and labour, even though it cleans the gear best, things look dirty within hours.
Also, due to the washing, some of the lubrication applied during manufacturing may also get washed.