Sartrebright

Before you think I'm going all existential on you, let me assure you I'm only getting grammatical. What's wrong with the following sentence?

Have less cavities when you brush with Sartrebright.

If you think it seems correct, please read no further.

For the last few months, I've noticed the use of "less" when "fewer" is called for, on commercial television, radio and even in my dining room. A strict grammarian, who'll go unnamed, said that his dentist took on less patients so he could give them better service. "Less patients, or less patience?", I teased. I'm not going into a grammar lesson here because I don't want to bore you even further, but I will tell you a little about Sartrebright.

Sartrebright is a toothpaste used mainly by French intellectuals which is why you've never heard of it. It comes in a distinctive black tube and the paste is gray. My college roommate and I made this up one night. We thought it was hysterical. I'm pretty sure it was a school night so there was no substance abuse going on. Just silliness.

You have fewer things to do in college than later on in life, unless you're me. Then your grammomometer
goes off at the slightest infraction.

Let's just keep that between you and I.