How can I stop accumulated Google Chrome background processes?

A grab-bag of chrome poisons:

pgrep chrome | xargs kill # this is basically "pkill chrome"

Same thing, but sleep for 1/3 of a second in between:

for i in `pgrep chrome` ; do kill $i ;  sleep .33 ; done

Keep on killing 'til the killing's done :

while pgrep chrome ; do pkill chrome ; done

Short and sweet (but won't exit until you exit manually) :

watch pkill chrome 

Might work? :

for i in `pgrep chrome` ; do kill $i && wait $i ;  sleep .33 ; done

If you don’t want to see “Google Chrome didn't shut down correctly. To repoen ...”, then it is important to signal only the root of the chrome process tree, like so:

pkill --oldest chrome

See full explanation.