I use these to clean my Boilcoils:
https://www.amazon.com/gp/product/B000BAT8PM/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1
I cut them in half/quarters and I've only gone through a couple of pads in ~6 months. Just a quick wipe down after cleaning, followed by one more rinse before drying...