A group of experts could theorise all day long about whether vacuuming is harmless, dangerous or suicidal.
Bottom line is that just opening up your computer could result in malfunction, and the chances increase the more chances you take.
The main thing is to consider the possibility that your computer could die at any moment in time, and make sure to have backup strategy to cope.
If you are feeling brave - use the air compressor. If you are feeling cautious, use a soft brush and gentle vacuuming. If you have plenty of money, buy an anti-static vacuum cleaner, wear wrist strap and unscrew case with antistatic tools whilst placing PC on antistatic work bench.
I use brushes and a good strong breath to clean my PC, with no bad result so far. But you have to decide for yourself how much care you want to take.
I might be tempted to use an air compressor, but I think I would worry more about mechanical damage than ESD damage. Either way, I see no need to do it, other than speed and laziness.
Hope for the best, but prepare for the worst.
Just my thoughts and experiences, feel free to ignore.