The rocks will have to be "cured" all over again. Once they dry out, they are no longer live rocks. To re-cure them, they need to be in a container with saltwater at the proper salinity and temperature... just like in your tank. A tub, power head (or power heads) to move the water around the rocks, test kit(s), and heater are all that are needed. A light can be added, but not necessary. You'll leave the rocks in the bin until Ammonia spikes, and then falls to zero. Nitrate will spike, and then fall to zero. Nitrate should be the only thing detectable. Once this happens, you can use the rocks in your tank again. I prefer to do a large water change in the tub, and let the rocks "cook" for another week or two, just to be safe. As flower said... bristleworms are a part of the cleaning crew. If there is an overpopulation of them, that means there is an overabundance of food. Reduce the food source, and the bristleworm population will be reduced. You can trap bristleworms (search for bristleworm trap) which will remove many of them, but since large populations are an indicator of excessive waste, treating at the source is the best method of reduction. Adding more snails such as nassarius snails can help reduce un-eaten waste accumulation, and compete with the bristleworms for their food source.
PS: Please don't dry your rocks out again...