He has a tool like that, but said it was the wrong size....
Monica, they do in fact come in different sizes.
Sounds like he needs to expand his tool collection.
If it was too large that would increase the chances of tearing the rubber as the lock strip was installed.
Too small and the tool would bind on the lock strip as well.
Some folks cause theirselves more grief by not using the correct tool for the job,not to mention upsetting their customers.