I have used two different 2.5 gallon sprayers and neither worked with the product. Both plugged tight in a short time. When I used the second sprayer I mixed the product in hot water stirring for 15 minutes and the sprayer still plugged in a very short time. Easiest application method was with a pole cleaning brush and a bucket of thoroughly mixed product. There was better coverage and no dealing with applicator plugging. If Corte*Clean recommends a particular sprayer they should indicate that on the label as well as more details on their product label about how to deal with applicator plugging. They should also indicate that what alternative application procedures can substituted without using a sprayer. Once applied the product does work as advertised on this web site. Our deck looks as it did when new. NOTE FROM CORTE LLC: Use a rag to filter out Corte Clean granules when pouring it into a pump sprayer or purchase the filter for the pump sprayer so it doesn’t clog. Application is definitely easier with a pump sprayer.