Silicone Grease

Hello,
I went to my local hardware store looking for food grade silicone
grease, but the owner only had dielectric grease.
The packaging says tha it should be kept away from the eyes, children
and so on, and when you swallow it, better get you ID and start walking
towards the cementary. One of the sale people apparently worked in an
"aquarium store" and thinks that dielectric grease is very safe etc.
Does anyone have tried that, or does anybody know waht grease is safe
for the tank?

Thank you
Yuriy