It’s common for decorative pillows to be made using leather, wool, suede, and other materials you cannot immerse in water. In this case, spot cleaning is a good option. You can also try a disinfectant spray, sprinkling borax over your pillow, and vacuuming your pillow.
For disinfectant sprays or borax, first, spot-test the treatments on a small area of your pillow—preferably the backside—and ensure they don’t cause stains or any discoloration. If nothing happens, you’re clear to continue cleaning it.