There are a number of silicone sprays. We have been using PB Blaster silicone spray for some peroid of time. I like to clean the window channels first. Clean the back channel, with warm water and dawn soap, then flush with copious water, slide the window back, and do that part of the channel. If you want to be "complete". you can take the widow out of the channel--but we have never had to do this. After the window channel is dry, (I usually fold a paper towel to get the water out of the channel and then a few more passes, and then let it air dry. Spray on the Silicone spray--and you are good to go for another year.