I normally always use those kind of effervescent tablets for fake teeth. They really work well. Every once in a while, I clean them with vinegar and warm water. That just leaves a horrible taste but gives me a great result.

At my local drug store they now also have special removable braces cleaning tabs. Haven’t tried them yet, but I’ll give them a try in the near future.

My orthodontist advised me to use" Retainerbrite " once per week and just to rinse the hawley on other days. In fact, I brush it every day with a soft toothbrush and ordinary soap. I wore my first hawley 12/7 for the first 6 months and would occasionally have drinks including  tea or coffee whilst wearing it . It had clear acrylic which  gradually became stained and I realised that must have been as a result of the tea and coffee. I was never able to remove that staining. I couple of years ago I got a new hawley which I only wear the at night. I asked for the acrylic not to be plain  transparent because of the staining of the previous one so the new hawley is transparent pink. I never eat or drink anything apart from water whilst wearing it and use the same cleaning regime. The side of the hawley in contact with my tongue remains very smooth and shiny. The other side looks more dull than it used to but still ok. That side of a hawley is never highly polished as the emphasis is on getting a good fit with the roof of your mouth.