With repeated shearing, hedges develop a profusion of outer twigs, die back in the center, and often show an increase in pest problems. Select quality tools. They will last longer and make pruning more pleasurable. For maximum effectiveness, sharpen blades regularly and dry and oil them after each use. Use a file or whetstone for sharpening hand tools, and have an experienced professional sharpen chain saws and power hedge clippers.
Tests show they are highly corrosive to metal.
Remember that no disinfectant can provide complete protection against disease.