I came across the recipe for making your own toothpaste.
The basic idea is sound, but I have a few suggestions that would improve upon this recipe.
Firstly, baking soda would probably be too abrasive, mostly because of the relatively large particle size. And I don’t think that substituting salt in its place is a very good idea, beef only because it would taste terrible.
Want would be much better is alumina, which is what’s in commercial toothpaste anyway. Alumina is aluminium oxide and is a very fine, free flowing white powder that is used to make abrasive pastes in many different industries, such as optical and jewellery.
It should be readily available from most chemical suppliers and shouldn’t cost much, which is the whole point of the exercise anyway.
But you will will still want some sodium bicarbonate (baking soda), in there, as it neutralises food acids. Perhaps three parts alumina to 1 part bicarb is what you want.
But I’d go very easy on the hydrogen peroxide, as you won’t need much to burn your skin. I’m not sure how many places sell it, but it’s available as a 50% solution from Tasman chemicals in Wangara, which is mighty strong. Make sure you take note of the safety instructions on the label.
As a starting point for toothpaste, I wouldn’t use it at any more than 1% (so a one in 50 dilution).
if you have a go at this, let me know how you get on.