Hi, I was in Phuket last March for 4 days just after I got my Red K-x. I went unprotected and the camera came back with no corrosion or sands. Went snorkeling and spend some time on the beach as well. Sorry dude, I don't see the point of carrying the camera if you gonna protect it with plastic bags and towels, then use your phone camera or PnS camera to shoot if you are afraid of what a little salt air and sand will do to you DSLR.
You should have considered the K-7 or K-5 for the WR body instead if you are worried by these factors, anyway we are living on an island and surrounded by the sea, salt water, sand and dust are unavoidable even if you are shooting at Marina Bay.
sorry but i think there's nothing wrong if pple want to take reasonable precautions to protect their equipment because you are certainly not going to be paying for the repairs if they take your advise and end up damaging their DSLRs. :nono:
even for WR bodies and lenses, the WR is for peace of mind and protection from environment outside of normal operating conditions. not for us to tempt fate with.