Silicone lube on silicone material… I don't think it may harm :/
About onaholes: most (if not all) of today's products are made of thermoplastic elastomer (TPE). Recommended is water-based lube. You may ask the maker but silicone lube should be okay.
The kind of lube that doesn't belong in onaholes at all are oil-based lubes and petroleum jelly (vaseline).
EDIT: nevermind. https://en.wikipedia.org/wiki/Personal_lubricant#Silicone-based
"Silicone-based lubricants are not usually recommended for use with sex toys or other products that are made from silicone because the formula may dissolve the surface making it sticky to the touch, and cause disintegration of the item over time. This damage may create a breeding ground for bacteria."
In short: unless the sex toy has been SPECIALLY crafted to be compatible with silicone lube, stick to water-based.