I fish a lot in warmwater lakes and I tend to get lazy about cleaning my lines sometimes. If I don't do it as soon as I get home it tends not to get done. If I notice they are not shooting or floating well I will clean them. If I pull the line between closed fingers, and it leaves dirt behind I clean it. If it leaves residue on my stripping finger I clean it. Some lakes I need to clean the line after every trip. Others maybe a dozen or more.