One thing that has done a lot for me is I've been doing more brushing without toothpaste. I do use toothpaste, but when I do it I treat it more as a fluoride treatment than as a tool to get off plaque. When I'm trying to get off plaque I use a dry brush.
As my post above indicates, this effect is really important. The plaque biofilm is really sticky. I'm not sure what's going on in GP's case, but when using a plaque staining dye to see what's going on, it's clear that toothpaste makes a huge difference in the ability to mechanically disrupt plaque. It's amazingly hard to do without toothpaste.
If everything goes as planned:
The abrasive is more likely to scratch what's on the teeth; and
the teeth are more likely to scratch the toothpaste if everything goes as planned.
That's what I do. Once to get rid of food debris. Then start with toothpaste. Then floss, rinse, and a quick brush again with toothpaste. But sadly too little too late with my teeth. They are screwed.
I rarely ate sweets as a child and avoid sugar. I rarely eat processed foods. Drink is another matter. I most likely have harmed my teeth from drinking beer/wine/smoothies and from being too rough when cleaning. I really miss my younger healthy teeth.
My teeth have felt horrible ever since they failed and were drilled and filled. And now bring me a lot of misery. Look after your teeth! Healthy teeth are incredibly attractive. IMHO.
I usually do a "milk-rinse", because I have the feeling it brings the pH back to neutral a lot quicker than water. But milk contains sugar, so perhaps a water-rinse after that is a good idea.
milk is a slight acid, so no, water would still be a better job of balancing pH, and also better because water contains no sugars or other things that might stick to your teeth.