Oil based lube with Helix Syn silicone going to create reaction that's toxic?

... I read constantly this warning for silicone toys, that's not ok at all to use them with oil based lubes, only water based lubes are permited.

I think you may be a bit confused. While most manufacturers of silicone based toys do recommend water based lubes for use, I've yet to read any prohibiting the use of oil base lubes with their use. What you will repeatedly read is the admonition to avoid using silicone based lubes or lubes containing silicone with silicone toys. The reason for this is the silicone molecules will readily bind to other silicone molecules forming a chemical bond which may be impossible to remove thus ruining the surface of the silicone toy.

I've been using coconut oil/shea butter as a lube for years with my Aneros Helix SYN, Eupho SYN, DeVice & Vice models with no apparent degradation of the silicone. Additionally, I think your assertion that oil based lube combined with the Helix SYN may create something toxic is wholly unjustified. Silicone is a remarkably stable compound that doesn't readily react with other compounds hence its use in a variety of chemically challenging environments including petroleum and food oil processing. If there were negative health consequences from using oil based lubes with silicone sex toys we would have heard about it long ago.
Good Vibes to You !

I'm using a mix of Cocoa Butter and Vaseline with my Helix Syn and no problems