If thorns then I'll leave the suggestions to others. I don't live where thorns are an issue and all my riding is on paved roads. So maybe someone with some Mtn bike experience will no more about those other products you ask about. Have you considered tubeless?
However when my tires go thin and are showing threads or very close to that, then flats are expected. Once I get the first flat at that point in the tires life I replace it.