I use Treclin gel but still have remaining clogged pores. What can I add to my regime to carry on seeing further improvements?

I have been using Treclin Gel at night for over a year (prescribed by doctor). It has improved my acne & clogged pores a lot, however, I still have some congestion on my chin - tiny blackheads and tiny little white dots that you can only see up close but I can also feel them - like tiny bits of gravel in the skin. I have read BHAs can help and was considering introducing them into my regime in the morning. Also any advice on moisturizer with SPF for clog prone skin would be great.