I had a small area of mulch, approximately 12 x 2 feet, it really was even less than that because I had large stepping stones within that area, and I wanted to lock in the mulch that surrounded those stepping stones. I did three coats it to dry two hours between each coat. Nothing held nothing was locked in. Yes, I shook that bottle for about 10 minutes, I also shook it after I put it in the pressurized spray bottle. It is, though I sprayed nothing but air over my mulch. Coupled with the fact that I had a hard time opening because some of the contents seem to have come out during shipping. I did not have trouble with any plugging up of my sprayer I guess because I shared so well of them that I wouldn’t purchase this ever again if you paid me too.