I know people scream not to use silicone but I never hear why.
Lot's of RV shops use silicone for different calking uses as well as Bigfoot industries continues to use it on there units..I have used it for years simply because I can get it anywhere and I live in a place now with just one hardware store..
There are many instances of people taking an RV in for repair and silicone was used for the calk by the RV tech..If it was as bad as reported on the internet,I would assume they all were negligent..LOL
To each his own, as we all have choices for our needs..