@Chip_Unicorn Remove the keycaps, and you'll have enough access to hit all the places where gunk likes to gather with swabs, rags, and canned air. Use a cheap but specialized keycap puller tool to lift straight up on the cap.
If it has scissor or butterfly switches, like laptop/notebook keyboards, then removing the keycaps is a different, delicate, and likely breakage-prone procedure that may make cleaning it infeasible.
@Chip_Unicorn For future cleaning that makes removing keycaps unnecessary, and if the keyboard has the right kind of switches on it, consider installing a set of typewriter-style keycaps instead of the original. Their short sides make the base and switch area so easy to access with tweezers and canned air without disassembly.