You have to angle your body such that the water drips straight down and not toward the front. It requires some practice to get the hang of.
If you use Beta or Nightly, you can turn on dev tools and use a custom addon list from a collection in your user account. https://blog.mozilla.org/addons/2020/09/29/expanded-extension-support-in-firefox-for-android-nightly/
I do not see a way to hide them on mobile.
Ratings are based on recent reviews from people in your region who use the same type of device that you Use.
You can probably get it down in one sitting. Just make sure you can get the angle right before actually going so you don’t end up with an infection.