i believe you are suggesting store bought hydrogen peroxide- I will try it. From what i have read just dip the toothbrush into the H2O2 (Hydrogen-Peroxid) and brush/swish for about a minute. I hope this is correct
also what i have decide to do is- try the apagard royal and renamel for a good while and then the neydent i will look at. i am not sure why you recommend neydent.
also i will wait for the toothpaste (i do not know what brand) that the clay people found helps be rid of the discoloration.