I have an aneros helix syn with the black silicone material. It seems the coconut oil is really difficult to wash off as, despite my scrubbing, crystallised coconut oil appears on it the next day, leaving these white dots. Even after washing you can see areas where the oil has stained it. I usually wash it with Lovehoney toy cleaner after use. I have tried leaving it (after normal cleaning) in boiling water for 10 minutes followed by scrubbing with dish soap and even that didn’t remove it all.
Also it’s mainly on the arms and the thin part of the stem. The top 3/4 of the stem, the largest part, never gets this problem which I suspect is due to the coconut oil rubbing off inside more than it does on the lower parts.
I think the oil has seeped into the slightly porous silicone.
It’s not the end of the world as I can just wash the crystals off before use but if anyone knows how to stop this for good then please do let me know.