I’ve been washing my ass wrong for 19 years…

I F(19) found out today that you are not supposed to finger your ass to clean it.today I found out today by talking with my friend F(18) why she cleans her ass with glitter soap (Treehut tropical glow body wash) I asked her if the soap irritates her insides and that’s when she informed me that I am not supposed to be sticking my fingers up my ass to clean it. For context my grandmother ( who molested me) taught me how to clean my butt and everything in general. Help, what do I do? Any tips for this situation.