Are you supposed to brush your teeth after treating it with a pen whitener?

I bought this pen whitener, but instructions don't say whether you are supposed to brush the teeth after using it, or not...It says ';Don't swallow';, but it doesn't say ';don't brush'; or ';do brush';...Are you supposed to brush your teeth after treating it with a pen whitener?
The pen whitener is a chemical that treats your tooth ( like bleaching). After the allotted time has passed for leaving the whitener on you will want to brush your teeth.