vaccuum <--vaccuum smilie also, get fan filters for your case fans and just dust/vaccuum it out every couple of weeks.
You can get PCB cleaner + flux remover. Also you can buy specail cleaning foam thats static safe. I have a bag of spare jumpers as a tribute to vacuming my motherboard without much care one time. Also watchout for static build up on brush attachments, and one more thing, don't do it with the system running.
one of those "depends" ones, i would go for it myself, but make sure it evaperates/drys off before running juice through it. Always be careful with cleaning substances, some like to strip the resin from the PCB. Q-Tip is a cotten wool rod yeh?
Compressed air cans work great!! Blows all of the dust off and theres no worry about it damaging anything or having to wait for it to dry.
I gently use an inch wide paint brush. Seems to work very well. Clean my fans with Q-tips Oh! yeah to be safe on your components don't forget to turn off the power and earth your computer before you proceed to prevent any static discharge during brushing. Edit: Canned air is good too!
If you use compressed air to blow out the case, fan blades, ducts, and PSU then take it outside as the dust will just find its way back in again. Never use compressed air from a generator as the oil in the line will wreck your PC. Panty hose makes the best filter material by far. If you don't have a source of used ones and are too embarrassesd to buy them then ask your mom, daughter, girlfriend or neighbor to get them. If you use isopropyl alcohol to clean thermal paste off a CPU then use 90% pure. Don't use the rubbing alcohol that's only 70% as it leaves a film. Rinse several times after removing the visible portion (of paste).
tbh i dont think it matters much (i've used alcohol alcohol to clean thermal paste off a processor once (mmm Bacardi 151...)... and I normally use 70% Isopropyl and I've yet to see a problem (been doing so for 3 years)
That film consists of many impurities. Could have long term corrosive effects. It may be a pain, but it would be better to clean off the CPU and heatsink and rinse them 3 times. The intial removal can be done with the help of a clean soft cloth or cotton tipped swabs. Apply no more than a half a beebee of paste with a razor or credit card edge. Then. scrape the paste until the thinest layeyer is applied. Make sure none gets over the sides because if it does then you'll need to start all over again. Anything remaining is applied to the heatsink.