Many cleaning products will harm the chemistry of your water - undoing all of the hard-work & time you've invested into testing the water & tweaking the chemicals to keep things in balance.
Cleaning products that are not designed for the pool environment can add nutrients to the pool, which consume your sanitizer and contribute to future algae growth. Some products are very acidic or caustic and can have an impact on the pH of your pool.
Orb-3 Enzyme Cleaner is designed for use around your pool. If you get some in the water it is a benefit rather than a problem.
It is also a highly effective, eco-friendly cleaner, and it works especially well on many common pool-area problems.