As stated above I would be patient and just let it clean up in the can. I like to move it around from time to time also to get flow to different areas. I have heard of others using vinegar or bleach to clean up before curing. Many use the acid but I don't like it because it removes layer or the rock. My new pukani and shelf I plan to clean with vinegar and water then dry in sun before I start the curing process.