At this point your deck, being made of wood, will raise small fibres, creating a rough surface. There are a few solutions available to tame these would be splinters.
If there is minimal damage to the deck, spot sanding is a good choice. Sand the problem areas and you will be left with a clean and happy deck. This is a good choice if you just want to clean your deck.
The second solution is a bit more work, but necessary if you are interested in refinishing your deck. First you will need to sand it. This will get rid of the pesky fibres, create a smooth surface, open the wood’s pores allowing it to absorb the stain/sealer and minimize splintering. Use 60-80 grit sandpaper on the deck and no higher than 100 grit on handrails. If you use too fine a grit sandpaper your stain/sealer will not be absorbed easily.
Your deck is now smooth and ready to be stained/sealed. Good luck!