How to clean the memory slot?

Question

Iron

He took out the old system unit from the pantry, changed the RAM and turned it on.
The bios squeaks like a cut that is a problem with the RAM.
I played with the slots, it turned out that it beeps only on one of the slots when a memory chip (any) is inserted in it.
Looks like over the years of inactivity, the slot has become clogged with dust, how can it be cleaned?
There are no purge units. Tried vacuuming - didn't help.

Answer 1

As an option - a can of compressed air and some kind of hard brush for hard-to-reach places

Answer 2

A spray can with air is the best option, we cleaned it so-so.