According to research, your laptop’s keyboard could carry 20,000 times more bacteria than your toilet seat.
Especially if you share your keyboard, it is important to keep it clean. Plus, I have yet to find a USB port on a toilet seat so let's not start using that.
Step 1: Turn off your computer/laptop or unplug the keyboard.
Step 2: Turn it upside down to let the crumbs fall out - Gently tap the bottom of the keyboard or chassis. I found "cleaning slime" as a helpful tool and it is cheap. It is also easily stolen as a childhood play toy.
How to make some - https://www.cnet.com/how-to/how-to-make-cleaning-slime-for-electronics/
Step 3: Use Focused Air blasts to dislodge the stubborn bits
If that doesn’t get everything, give the keyboard a once-over with a vacuum. Make sure that you use a small attachment and the lowest power setting. (The last thing you want is to suck up one of your keycaps.) If you have a small handheld vacuum, even better.
You can also use a can of compressed air. Spray the air in a zigzag pattern so you don’t miss any nooks and crannies, and make sure you hit all sides of each key. If you don’t have compressed air, you can try another device that blows air (such as a blow dryer). Do not spray air directly under the keycaps; it could damage delicate electronics.
I have repurposed my lens cleaners for cameras for this - use a rubber air blaster for this.
If you’ve done all of this and still have some gunk under your keys, you may need to pop the keys off. Whether you can do this will depend on your laptop model. Look up your laptop model and follow the manufacturer’s instructions. At this point I would just get another keyboard and avoid the aggravation. It is also one of the advantages of having a mechanical keyboard - the keys pop right off and pop right on.
Step 4: Disinfect - Think moist not dripping wet.
Next, clean the surface of the keyboard itself to eliminate germs, smudges, and stains. First, wipe everything down with a disinfectant wipe. Avoid any wipes that contain bleach. If you don’t have wipes, a soft cloth with some rubbing alcohol can also work. Wipe the keycaps one at a time, as well as the areas between them, to make sure you get every spot.
You want to avoid getting any liquid under the keys, so don’t use any cloth that’s dripping wet. If needed, wring your wipes out before you use them. Do not spray water or any cleaning liquids directly on the keyboard.
Next, go over everything with a damp cloth (again: damp, not dripping). Ideally, you’ll want to use a microfiber cloth. If you don’t have one, another cloth is okay. Try to avoid anything abrasive that could scratch the keys, like a paper towel.
I found the micro cloths at Harbor Freight a cheap and reliable cleaner I can reuse.
Finally, dry the area off with another soft cloth.