It's glorious seeing G-Shocks being worn for their intended purpose. You can just clean the watch once or twice every two weeks or so if you want it to be around for longer. I found that running the individual pieces (module, bezel, band) after disassembly under tap water and washing them with regular hand soap works best. Use a soft bristled toothbrush to clean the particularly gnarly bits, especially the insides of the resin pieces. I use the same method on my metal watches and am very satisfied with the results on both families of watches.