Yes, I have removed a limiting Saturn-Mercury opposition effect, and did workings to improve memory and intelligence. But removing limits caused by that aspect had the most notable results so far. Firstly, I recommend for you to check your natal chart to see what kind of aspects there are to your natal Mercury and work on your weakest point first either with a spiritual square working or Munka working to remove negative karma. From there on your intelligence workings should have a desirable effect. Please also note that you need to put your brain to work, which means you need to actively practice things such as languages (grammar, syntax, and so on) or learn a new language and calculus. Learning anything new will help you improve your mental faculties, though. You can use Thoth's Demon Ritual for extra guidance on your path for greater intelligenc.