[Leica] what to use to clean the image receptor (processor or whatever it is called) on my Sony a7r camera

[Stasys Petravicius]

Hi All - There are several soft spots visible on images when I enlarge them on my laptop. I wrapped a Q-Tip with a piece of lens tissue and lightly brushed the spots and tried to blow the dust? out of the camera cavity. Did not do much. I have lens cleaner fluid- but did not want to cause any light streaks on the surface of the image processor - maybe there is better fluid -  i.e. isopropyl alcohol, or Absolute Vodka?  
Any suggestions other than sending it in for service to Sony or ?
Also- we will be taking a cruise to Antarctica the first of November. Any suggestions for photography, batteries, or otherwise?
Thanks, Stasys Petravicius