that may harm its positive effects.

The only positive effects that it has is that it lights up the room. As long as you don't get the electric parts wet, it'll keep doing that. So, use any cleaner that you like.

Hit it with the air compressor.

I vacuum mine with the little dust brush on the end of a hose. Have vacuumed it for yrs. I have several salt lamps. Its never hurt any of them.

Not sure if it’s safe but on my bedside slams I uses a lint roll.

Lamps rather... sorry lol

It's just like any other solid material (plastic, glass, marble, ...). If it works, then it's fine to clean it that way. It can be damaged by cleaning agents. But it does take something reasonably aggressive to do so.

For what it's worth, you can even clean it with water (e.g. a damp cloth) as long as you don't get any electrical parts wet. It's not as if salt dissolved very easily unless you grind it into tiny crystals or used hot solvent. A little bit of dampness isn't going to do anything.

When you think about your lamp, don't think "cotton candy", instead think "block of marble". That'll give you a better sense of what you can use for cleaning.