what materials can I use 2 clean a potentially smurged plate

I recently opened my hard disk drive(hdd) in a fairly dusty environment which was my bedroom.I admit that it was a very dumb idea but i did not know that the plate inside is sensetive to dust and all.

I will probably get a new one soon as this was my only drive and my windows 10 files where in there.When i tried to boot the computer(toshiba satellite l505d)it says "please insert a bootable device" and i can hear a click sound roughly every second followed by another longer click in the same second.After about 20-25 second of that,the clicking sounds cease to annoy me and the drive sounds normal though it still wont be detected by my other 2 computers via usb.

The drive is a hitachi hdd 5K500 B-320 and its 320gb capcity i almost full(or was;() and the plate speed is 5400rpm and i have already violated the warrnaty. It does not have anything that important as i had a big chunk of the data in my google drive and i can always download the content that was not backed-up but it will be awesome if i save the drive and the data on it.

I live in zimbabwe and i dought that there are any companies that have iso100(one of those sterrile environment) rooms and if they are there they will punch a huge hole in my very thin wallet to fix the hdd.

I tried installing windows 8 using a disk but my computer does not detect the drive and the same happens when i choose the repair this computer option.

Is there any method i could use to get the drive working again.I was on microsoft forums and i read about a person who had a similar issue in 2009,where -by the drive was submerged in sewage for an hour:o and he was told to use a soft cloth and alchohol to clean off any smudges on the plate.I am yet to ask him if he succeeded in this tricky adventure.

Please suggest a method i could use to clean the plate,which materials i require and how to create a fairly sterrile environment at home.

Thanks a lot.