I used a silicone spray to waterproof my white canvas shoes. Now they're stained. How can I remove it?

Question:So my white Converse Jack Purcell shoes are a lovely white color. I wanted to keep them that way, so I used a silicone based spray to keep them waterproof and supposedly stain free. I wash them in the washer, then put them in the dryer. And now, I guess the silicone got cured in the hot heat and now my shoes look like I dipped the tip of my shoes in pee.

I've tried scrubbing by hand, soaking them for a while, used whitening toothpaste, made a Clorox bleach paste, and I'll try using baking soda next.

Does anyone have any idea how to remove them? They are like my favorite pair of shoes. And I've only used them maybe less than a dozen times. I'll utterly sad and depressed. I feel like I've wasted my money on a beautiful pair of shoes that are now ruined because I tried to keep them that way.

Answers:
Heated silicone does yellow. It is not a reversible process. Any thing that will take the silicone off is going to ruin your shoes. We use silicone based sealants in construction all the time and the stuff that removes it is very caustic.

Sorry