Questions about pressurized gas cleaner

depends on the type and amount of dust, but if that doesn't help, it must be so bad that dismantling is the only solution.
just disconnect everything from the power supply first, try not to hold the can upside down and avoid turning the fans, as this will also generate some current.
by far the best is to avoid dust from the beginning, e.g. with dust filters in front of the fans.
if you also make

A spray tube is included if that answers the question.

the aerosols serve to build up pressure and may also escape as liquid, e.g. when sprayed upside down, but are not harmful to the electronics and evaporate quite quickly - nevertheless, it is recommended to disconnect the power and allow any heat to dissipate in order to avoid temperature shocks, which in extreme cases can lead to cracks, for example

As far as cleaning power is concerned, compressed

Probably because the pressure drops a little, which raises the temperature a little.
But as far as I know, this is not water, but butane. Should be easy to check with a lighter (just don't light it while you are spraying, it can go in your eye).

So far, I have mainly used the spray to remove dust from the hardware in the computer. CPU, RAM, mainboard, etc. However, since the spray only works with compressed air, it should also be no problem to remove dirt from the parts of a projector. Since the liquid air evaporates when used as a gas, it becomes cold. So I wouldn't hold it too close to the objects to be cleaned. I would start with a distance