I assume you are using FLWM, in this case the following might do the trick:
rm -f ~/.wmx/Applications/getFlash10
I hope you have checked that 'getFlash10.tcz' is not any more in your 'onboot.lst' file, AFAIK this is what 'appsaudit' should do for you. I understand you have already removed all "getFlash10.tcz*" files from the '.../tce/optional' directory.
Did you actually reboot after all these changes, or are you using a persistent 'home'? Because that is in my view the only way that the context menu entry might remain even if the extension is not any more in 'onboot.lst' and in the 'optional' directory.