Silicone baking mat?!
Answers: keeps getting oily when stored after cleaning in the cupboard
Put a drop or two of household bleach in a cup of water. Dip a paper towel in the mixture and wipe down your mat after washing it, then wipe again with clear water. I have been doing this for over a year with no problems. I have always added a few drops of bleach to the water when I wash plastic containers and glasses, so that's why I tried it with one of my baking mats.
roll it up and store it in a tube type container..or, give it to Good Will and use parchment paper...works great, inexpensive, easy to find in stores.