I agree that that’s a really high accuracy, (mine is at 88%) how many lessons do you do a day? And how many apprentice items do you have? Generally the amount of reviews you get daily is roughly the same as how many apprentice items you have (plus or minus like ~10-20).
With accuracy that high you might want to pause lessons for a while to let the number of your apprentice items go down, it should only take a week or so (depending on how much you have). I generally like to aim to have my apprentice items be less than 100.
To answer your question, you can use userscripts to do self study, stuff like this.
However, you just might be doing too many lessons daily and too little reviews, doing 10-15 lessons a day with reviews twice a day (zero the reviews out both times) should keep the apprentice level at a manageable number.