when I first start use cloth wipe , I only have a toddler and be use they infrequently . after one week I notice a burnt smell and find my pad have brown dry spot on it . once I have a newborn and be use wipe regularly again , I give it another try . first , I wipe down the inside of the warmer in case that be the problem . the pillow last a little longer this time until I notice a funky smell on my wipe . now on my third pillow , I have be flip it every day and add more water ever 2-3 day . it be still develop a funky smell . Ugh . I be go to use the warmer without it as reviewer have suggest and see what happen . to be fair , we have hard water and we have the same problem with we humidifier filter . no matter how often I flip they , replace the water , or clean the humidifier , they get crunchy and gross quickly . -lrb- that be , until I discover the antimicrobial solution you can add to they . I wish there be something like that for these . -rrb-