I had been using these with my cloth wipes in the Premium Wipes Warmer and was tired of them drying out too quickly and having kind of a funky smell. The package says they should be replaced every 3 months, but I found they really only last a little over 1 month. I was getting ready to buy my second set of replacement pillows when I decided to try using the warmer without them. So far I don't notice much difference! The cloth wipe closest to the bottom did dry out a bit, but it was still usable. I think I will deal with a dried out wipe every once and while and save the $7 or $8 to replace the pillows every month.