To clean the lenses from dust and dirt, I use two tools: pencil lens pen and a photo pear.
Cleaning takes place as follows:
You can buy both a photo pear and an ordinary small enema (it is important that there is no talcum powder inside). These devices look like this:
The task is to blow off dust from the surface of the lens or matrix. It can also be used in product photography to clean objects from small dust particles.
The same devices can clean the matrix... But if the matrix is completely dirty, it is better to seek professional cleaning.
You can buy these simple tools for dealing with dust both in local stores (with a considerable surcharge) and на AliExpress: