Issue With Soap And Cleanliness
This is not the spirit of Islam to give directives beyond one’s capacity. The directives are very simple and straighforward. You need to not let these doubts go amok and turn into an OCD. Just wash your hands via soap, and if you notice actual filth somewhere on your body, you can clean that; mere spalshbacks do not make you impure, neither does soap bubbles in the soap holder. Going into unnecessary intricacies like how soap works etc. is against the spirit of Islam.
And sorry, I also just wanted to confirm: it’s reasonable to ignore any splash backs of water during istinjaa even if there’s suspicion that this water contacted impurity, right?