I used this GE silicone and it worked, GE white sikicone kitchen and bathroom caulk. It is 100% silicone. The one i used, on the label, in a gold box says, 3hr shower ready, 5 year mold protection. It also says, premium waterproof silicone in a red area. Not sure why it worked but it did. I bought it to patch some spots in my shower and then used what was left to try making a mold.
i did let it sit outside for a couple of days before using it. It stunk to bad to bring it to the basement, lol