Anti-slip inserts are a useful way to avoid accidents on slippery decking. Most companies provide a guarantee. Our for instance covers the anti-slip properties for 5 years. Because the strips are made with Bauxite which is a sedimentary rock, some people avoid using them in areas where young children play because falling on one would almost certainly skim the skin from a knee, although others argue they would rather a skimmed knee than a running child slip and have a nasty accident.
There are various types of insert. The Deckwright inserts from WJ come in a kit which contains 25m and adhesive, are easy to cut with tools in the garden, and as long as the deck is clean and dry when installed, have a good lifespan.
All that being said, the quality and longevity of the finish really depends on whether the instructions have been properly followed on installation….