I had the same problem because I recently got a SP TB-1 tube mic and don't want to constantly connect and disconnect the cable and clip mount, so I got a recloseable food storage bag (gallon size) and a packet of silica gel from some glucosamine/chondroitan that my wife takes and put the baggie over the mic with the silica gel in the bottom of the baggie and then close the baggie from each end so that it is fairly tight around the boom and cable. That keeps the dust and dirt out of/off the mic and the silica gel helps to keep the humidity and moisture down inside the baggie.
BTW, got this idea because the TB-1 came inside the carrying case enclosed in a recloseable baggie with a small packet of silca gel. I figure if the factory thinks it's a good thing to do, then I would too.
Tom
PS Do remove the baggie before doing any recording!!!!!