We usually recommend water based lube to use with silicone toys because some silicone based lubes interact poorly with some silicone toys. Its simpler to just stick with the water based lube, especially because we love them so much anyway. But if you, like me, are in the throes of a love affair with silicone lube (it lasts so long! it never gets sticky! it works under water! I only need a little! it makes my hair shiny! I can put some on a steel butt plug and wear it to math class!!) and are determined to use it whenever possible, you can do a spot test on the base of your toys before dousing them in a potentially damaging product. If after much rubbing you wash it off and the spot feels the same as the rest of the toy you’re probably good to go. If it feels tacky, best stick with the water based stuff. Generally, the highest quality silicone toys will mix fine with a high quality silicone lube.
Having banished oil based lubes to the far corner of our store (and sometimes minds), we were caught off guard when someone asked if oil based lubes will harm silicone toys. My initial thought was that they would work together fine, but it sounded like the perfect science experiment. I tested our oil based lubes on an old silicone Fun Factory Bubbles vibrator: Stroke 29, Him Cream, Please Stroke Cream. The results? No bad interactions whatsoever! So yes, it is safe for dudes to use oil based lubes with silicone toys in their butts and on their dicks. But remember that oil based lubes should never be used with latex condoms and can cause problems for vaginas.
Since the test toy was still in perfect condition after the oil based lubes, I decided to check out a few silicone based lubes on it as well. I tried Eros Pjur, Uber Lube, Pink, and Sliquid Organics Silk; none of them had a bad interaction with the Fun Factory silicone toy either. I still recommend doing spot tests with silicone toys and lubes on your own though.
You can read more about lube here.