The Dehisser is primarially used to eliminate the nouse found from analog tape recordings and mic pre-amps...
I can see where Noise Gate could help suppress low volume noise, but it will also suppress sound I think you want to keep. Still, the effects in the software are non-destructive, so you can try them out and if you do not like them, you either do not accept the change or CTRL+Z to undo them...
You can try out the MultiMax, but I am not sure what you need cleaned, so it is harder to make suggestions if I am not sure what anomaly might be in the sound you have recorded.
I would probably open up the Mastering Suite to see if it could help me eliminate or suppress the sound anomalies. That would be found under the drop down menu 'View' then "Mastering Suite".
As for settines, I am not sure what you will like the most, so try those out. I would probably start with the very tio drop down once in the Mastering Suite to select speech, if that is in fact what you have recorded from Skype.
I have never tried it before. I also would suggest trying the Magix Audio Cleaning Lab... even as a demo to see if you can get that to work out the audio restoration for that Skype recording.