Well then you can take care of yourself, there is no 'gui' way, nor will there ever be. (unless one of those tweak tools has or adds
To do so -
Locate the app(s) in question .desktop in /usr/share/applications & open in a root text editor
add this line to the .desktop
Small insignificant example -
when searching "start" I don't want to see ibus
So opening ibus.desktop as root, add line, save, it no longer appears
If using gksudo gedit then you can make life a bit easier by also having /usr/share/applications open in nautilus.
Once the root gedit is open just drag & drop the .desktop you wish to disappear from Dash app lens searches onto gedit window, paste in line, save, then DnD the next one, ect., ect.