Deoxit for cleaning potentiometer tracks:
https://www.amazon.com/Hosa-F5S-H6-DeoxIT-FaderLube-Spray/dp/B00006LVF1/ref=sr_1_4?keywords=deoxit+fader+lube&qid=1578695010&sr=8-4
https://www.amazon.com/Hosa-F5S-H6-DeoxIT-FaderLube-Spray/dp/B00006LVF1/ref=sr_1_4?keywords=deoxit+fader+lube&qid=1578695010&sr=8-4