Renewer powder is just cornflower so don’t waste money on the branded product.
You’re supposed to use it inside and outside.
I initially tried the powder with my Fleshlight sleeves and found it very messy to use and if you don’t wash it out before you use the toy again then the powder forms a messy paste with the lubricant.
I stopped using renewing powder after a couple of attempts and my toys seem to have lasted OK.
In my experience it’s just a feel thing - without the powder/flour it just ends up feeling a little tacky vs feeling like skin as is the intention.
If it became pasty you’re probably using too much of it.
Agree with the others here. It’s mainly just a feel thing more than anything. While my toys are in rotation, I don’t bother using the powder daily. But if I’m then swapping them out for another one I powder it before putting it away - and only on the outside. Because the paste thing that @rockstar mentioned happens when you put it on the inside and it’s pretty off-putting when you’re trying to get off!
It basically helps maintain the silicone from deteriorating and getting worn so is a good idea to put it inside the areas to, and like @rockstar mentioned to just use cornflour instead