SmartDesignGirl, Other than a very few colors (white, almond, clear, gray, black), I have not seen any 100% silicone caulk in the stores, and no sanded at all. Home Depot has none stocked, Lowes has none stocked, two local tile shops have none in any color (just the siliconized latex that matches their grouts). Thanks for pointing out that silicone will not stick to old (cured) silicone.

Clean out the grout with a utility knife and/or a single sided razor blade. Get it ALL out and vacuum up any residue. Wipe down with mineral spirits. Now, use ONLY a pure silicone caulk...NOT a "siliconized acrylic." I like to 2/3 fill the tub and then caulk it. Let it sit for 24 hours. Filling the tub allows it to "gap" as much as it can. When you drain, the caulk pushes up...rather than pulling apart when you fill it with water (and bodies)

You can ignore any advice you want. You have a change of plane there. It is industry wide specs that call for a silicone joint at all change of plane. Care not what the handyman used or is saying, its obvious you doubt their novice advice and its obvious by the quality of the work they are incompetant. Your big concern now is the proper way in which you remove all residue so Silicone can bond properly and so that you dont leave behind any MOLD prone residues under the new silicone install. So many clowns come here with mold under their poor attempt to correct a change of plane by improperly cleaning out latex based caulks and replace with the proper material. Then later claim their un-mold-abale silicone is producing mold. Its an age old mistake and ive told you exactly how to approach the repair. Now im not looking for likes here or thank you's . But if you speak to any one single tile professional that follows the TCNA/ansi youll see what im saying. The way forward is in your hands. Acetone . Use it. and since you are spanning a larger than industry standard 1/8" joint you need to choose your flash point and type silicone properly theres no less than hundreds of 100% silicone blends/types out there.

I wouldnt go with 100% silicone because paint doesnt adhere to it. (if you ever changed or touche up paint color. I would recommend Grout caulk. It will match your grout and look better and you would be able to touch up paint on it if you needed some touch up.