1. Natural bristled brushes(horse hair) are less likely to carry a lot of static. Synthetic fiber brushes are likely to carry more static and should be avoided unless they are specifically made for cleaning electronics. Most people don't use brushes. (see point 2) I'd say it's a good idea for heat sinks but avoid contact with PCBs without doing a lot of extra research. Anti-static brushes do exist.
2. A data-vac duster is the ideal method of blowing out a computer. Any compressed air source would be fine. A lot of people balk at the price tag on the duster but they last a long time and are just as effective as canned air. Most importantly they don't run out. Use short bursts. Make sure you hold fans still as spinning them really fast can mess up the bearings.
3. You probably don't need or want to disassemble the GPU. Just use your air source to blow it out. If you do decide to pull the heat sink off. You could very easily damage the thermal pads...they are fragile. So I would go ahead and get some spares before hand. And make sure your thermal paste is non-conductive. If you aren't sure, get new paste.
4. Thermal paste is generally pretty cheap. If you aren't sure about it, get something new. Check with Noctua about the longevity/shelf life of their paste. Assuming it's been stored in a cool dry place with the cap properly secured. It might be okay.
5. Use an anti-static wrist strap clipped to your case. Moving air can generate lots of static in a dry environment particularly when large amounts of dust are involved. That lightning during volcanic eruptions is static discharging. (all lightning is technically static discharging but volcanoes are more relevant and visual example in this case.)
6. Take your time. You might want to consider getting an anti-static mat. If you are swapping paste out get some lint free alcohol wipes or lint free cloths with a bottle of isopropyl alcohol. Higher the percentage the better.
bonus. PPE. Wear safety goggles and a mask to keep dust out of you throat and eyes. You don't know whats in that dust. (most people don't pay any attention to this. Thus ... bonus.
Thank you for the reply, I'll also reply in numbers as to not mix things up
1. Only have synthetic brushed
not sure if I should proceed anymore but I did have a look at it and yeah... has some fair bit of work to do but with the proper brush (do you have any ideas?) just throwing it out there how about a tooth brush? then I guess those are synthetic so they are right out of the running from the start
2. Can't find it in our place (I don't live in the US) though I can order from newegg,amazon cause they just struck a deal to deliver to countries they didn't deliver before I don't think it'll make it in time for me to use and clean this week/month, maybe I'll have to compromised for now and just buy 2 cans of compressed air from the computer shops and facepalm for contributing to the "environment destruction"
3. I see, more of a wait and see approach, if the air can clean it out why bother taking it apart unless I am replacing the thermal paste and pads or ???
4. Had a look at their site and there is no sort of expiration after it's used... but I did email their support for good measure, this is the link of the NT-H1 specs that I looked at https://noctua.at/en/nt-h1-3-5g/specification
and yes it's been stored back to its box on room temperature and away from direct sunlight (the NH-D15 box and another big box that it's stored in) though "slightly" humid thanks to our country location but maybe it'll not have that big of an effect on it... we'll see on the reps replay maybe?
5. Don't have one even for sale, maybe I'll just touch something metallic first (bare metal not painted metal) before I get to work as to "reduce/nullify" ESD (or at least that's what I am told)
6. Same reason as number 5 but still thanks for reminding me to use isopropyl alcohol/alcohol wipes/lint free cloths but if I remember when I first installed the cooler and had to clean the surface of the processor I think I used a micro fiber or maybe kitchen towel not sure
7. Does cleaning the I/O shield help clear up electric grounding towards the audio inputs? had a mic go bad and I am suspecting it's the dust that's casuing the havoc
for the bonus thank you again for the reminder and yes I kinda remembered i kinda cough a bit too hard for comfort while close to the unit when I was upgrading the cooler so maybe a mask this time and a goggle if I find one
and again thank you for your reply