He also may be doing it to that particular pillow because it smells like you and he LOVES you .... of course you never would imagine he would show his love for you so demonstratively, but take it as a compliment! My RB Goldie and now Mishi do their thing with Muffy because I sometimes sleep with it and it has my scent on it. (I know my secret is safe here, right?) It's just the right squishiness for them; I guess to them it feels like another cat or maybe mama cat

Wash the pillow and continue to have your favorite, worn-in hugger pillow - I KNOW how important those are! I recently replaced my "hugger pillow" with one of those new Homedics "squish" pillows - it LOVE it and Mishi leaves it alone (for now).