Handy for Lubricating Plastics & Rubber.
There are times when you need to Lubricate something that's made of Plastic or a bearing fitted with Nylon Washers. The majority of Oils are one way or another Petroleum-based and using them on anything other metal can cause trouble further down the line.
Silicone based Lubricants are more suitable for use where Petroleum-based ill advised, and although I don't own a Treadmill I do own several Cycles that I use Silicone oil on.
I use it on Suspension that has a lot of Rubber Washers in it's make-up. It's also particularly useful on Curtain Rails to get them moving smooth & fast again.
Many things around the home can benefit from the use of Silicone Oil with it's less corrosive properties. I can recommend you buy some.