Why not just rename the executable to a different name? Or just relink it. For example for firefox this would be the easiest way:
We have to hide the folder name, so make a new directory
sudo mkdir /usr/lib/icefox
Next we make a link to firefox executable
sudo ln -s /usr/lib/firefox/firefox icefox
Now modify the firefox launcher
sudo vi /usr/lib/firefox/firefox.sh
And there change the MOZ_LIBDIR or MOZ_APP_NAME variables appropriately so they should read:
Leave all other lines untouched.
After these firefox should show up as icefox in ps/top/htop.
If you don't like this method you have to modify the source code of top/htop/etc. All of these reporting programs get their data from the /proc filesystem. For e.g. the file which you should modify in htop's source is this. There you have to change the ProcessList_readCmdlineFile function. Just insert an
if section after the
command[amtRead] = '\0';
line in which you check whether it is a process of which you want to hide it's name and if it is, then modify the
command char array to what you want. Then after the changes you have to compile htop for yourself and use this modified version instead. But this method is not simple and I don't like it.